Wireless communication methods and apparatus supporting multiple modes

ABSTRACT

Wireless terminal operation is coordinated to be responsive to dynamic communications frequency spectrum reallocation between infrastructure based communications usage and peer to peer communications usage. Methods and apparatus in which mobile nodes switch between cellular and peer to peer communication modes of operation are described. Broadcast signals, e.g., beacon signals, are monitored and detected by the mobile node to ascertain a current spectrum usage designation, and the mobile node switches operational modes in response to detected changes in the broadcast signals.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/758,011 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR USING BEACON SIGNALS FOR IDENTIFICATION, SYNCHRONIZATION OR ACQUISITION IN AN AD HOC WIRELESS NETWORK”, U.S. Provisional Patent Application Ser. No. 60/758,010 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR FACILITATING IDENTIFICATION, SYNCHRONIZATION OR ACQUISITION USING BEACON SIGNALS”, U.S. Provisional Patent Application Ser. No. 60/758,012 filed on Jan. 11, 2006, titled “METHODS AND APPARATUS FOR USING BEACON SIGNALS IN A COGNITIVE RADIO NETWORK”, U.S. Provisional Patent Application Ser. No. 60/863,304 filed on Oct. 27, 2006, U.S. Provisional Patent Application Ser. No. 60/845,052 filed on Sep. 15, 2006, and U.S. Provisional Patent Application Ser. No. 60/845,051 filed on Sep. 15, 2006, each of which is hereby incorporated by reference and all of which are assigned to the assignee hereof.

FIELD

The present invention is directed to methods and apparatus for signaling in wireless communication and, more particularly, to methods and apparatus for using signals for identification, synchronization and/or acquisition.

BACKGROUND

In a wireless network, e.g., an ad hoc network, in which a network infrastructure does not exist, a terminal has to combat certain challenges in order to set up a communication link with another peer terminal. One challenge is to make the terminals in the vicinity to be synchronized to a common timing and/or frequency reference. A common timing and/or frequency reference is crucial for the terminals to establish communication links. For example, in an ad hoc network, when a terminal just powers up or moves into a new area, the terminal may have to first find out whether another terminal is present in the vicinity before any communication between the two terminals can start. The general solution is to let the terminal transmit and/or receive signals according to certain protocol. However, if the terminals do not have a common timing notation, it is possible that when a first terminal is transmitting a signal and a second terminal is not in the receiving mode, the transmitted signal does not help the second terminal to detect the presence of the first terminal.

In view of the above discussion, it should be appreciated that there is a need for new and improved ways for identification, acquisition, and/or synchronization, especially in a wireless system in which the network infrastructure may not be available.

SUMMARY

Various embodiments are directed to methods and apparatus in which wireless terminal operation is coordinated to be responsive to dynamic communications frequency spectrum reallocated between infrastructure based communications usage and peer to peer communications usage. In some embodiments, a wireless terminal monitors for changes in broadcast signals, e.g., beacon signals, to detect a reallocation of frequency spectrum.

An exemplary method of operating a wireless device comprises: establishing a communications link with a base station; monitoring for broadcast signals from said base station while maintaining said link; and in response to detecting a predetermined change in at least one of said broadcast signals indicative of a change in communication mode of operation from a cellular mode to a peer to peer mode of operation, ceasing to maintain said link. An exemplary wireless communications device, e.g., mobile node, includes: a link establishment module for establishing a communications link with a base station; a broadcast signal monitoring module for monitoring to detect broadcast signals from said base station; a mode determination module for determining a communications mode of operation from at least one broadcast signal from said base station detected by said monitoring; and a mode control module for controlling the wireless terminal to operate in the mode determined by said mode determination module, said mode control module dropping said established link when said mode determination module indicates a change in communication mode of operation from a cellular mode to a peer to peer mode of operation.

While various embodiments have been discussed in the summary above, it should be appreciated that not necessarily all embodiments include the same features and some of the features described above are not necessary but can be desirable in some embodiments. Numerous additional features, embodiments and benefits are discussed in the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary communications system supporting both access node based communications and peer to peer communications implemented in accordance with various embodiments.

FIG. 2 illustrates two exemplary spectrum bands available to be used in a geographic area.

FIG. 3 illustrates a ladder diagram of an exemplary method of obtaining and utilizing spectrum information implemented in accordance with various embodiments.

FIG. 4 illustrates an example of utilizing timing synchronization information implemented in accordance with various embodiments.

FIG. 5 illustrates an exemplary diagram of receiving paging and being in a peer-to-peer or TDD session implemented in accordance with various embodiments.

FIG. 6 illustrates a flowchart of an exemplary method of operating a wireless terminal to determine data rates corresponding to potential links with alternative nodes, e.g., a base station and a peer wireless terminal, and selecting a node to communicate with in accordance with various embodiments.

FIG. 7 illustrates a ladder diagram of an exemplary method of using beacon and/or broadcast channels to temporarily convert infrastructure spectrum band for non-infrastructure based service implemented in accordance with various embodiments.

FIG. 8 illustrates two exemplary ad hoc networks in two geographic areas, implemented in accordance with various embodiments.

FIG. 9 illustrates exemplary spectrum bands available to be used in two different geographic areas.

FIG. 10 illustrates exemplary system beacon signals transmitted in the ad hoc networks in two different geographic areas.

FIG. 11 illustrates an exemplary wireless terminal implemented in accordance with various embodiments.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is a drawing of a flowchart of an exemplary method of operating a wireless terminal to communicate with another communications device in accordance with various embodiments.

FIG. 13 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.

FIG. 14 is a drawing of a flowchart of an exemplary method of operating a wireless terminal which supports both peer to peer communications and communications with a base station in accordance with various embodiments.

FIG. 15 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.

FIG. 16 is a drawing of a flowchart, of an exemplary method of operating a base station in accordance with various embodiments.

FIG. 17 is a drawing of an exemplary base station in accordance with various embodiments.

FIG. 18 is a drawing of an exemplary beacon signal transmission apparatus in accordance with various embodiments.

FIG. 19 is a drawing of a flowchart of an exemplary method of operating a beacon signal transmitter device in accordance with various embodiments.

FIG. 20 comprising the combination of FIG. 20A and FIG. 20B is a drawing of a flowchart of an exemplary method of operating a base station in accordance with various embodiments.

FIG. 21 is a drawing of an exemplary base station in accordance with various embodiments.

FIG. 22 is a drawing of a flowchart of an exemplary method of operating a wireless device, e.g., a mobile node, in accordance with various embodiments.

FIG. 23 is a drawing of an exemplary wireless terminal, e.g., mobile node in accordance with various embodiments.

FIG. 24 is a drawing of a flowchart of an exemplary method of operating a mobile communications device in a system including a base station in accordance with various embodiments.

FIG. 25 is a drawing of an exemplary wireless terminal, e.g., mobile node, in accordance with various embodiments.

FIG. 26 is a drawing of a flowchart of an exemplary method of operating a wireless device, e.g., a mobile node, in accordance with various embodiments.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawing of a flowchart of an exemplary communications method in accordance with various embodiments.

FIG. 29 is a drawing of an exemplary wireless terminal, e.g., mobile node, in accordance with various embodiments.

FIG. 30 is a drawing of an exemplary communications system in accordance with various embodiments.

FIG. 31 is a drawing of an exemplary wireless communications system which supports both peer to peer communications and cellular communications in accordance with various embodiments.

FIG. 32 is a drawing illustrating exemplary beacon burst time position hopping in accordance with various embodiments.

FIG. 33 is a drawing illustrating exemplary beacon burst time position hopping and beacon symbol tone hopping in accordance with various embodiments.

FIG. 34 is a drawing illustrating exemplary coordinated timing in a peer to peer communications band in accordance with various embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary communications system 100 supporting both access node based communications and peer to peer communications implemented in accordance with various embodiments. An infrastructure base station 108 is coupled with a big network, e.g., the Internet, through a network node 110 via a wired link 111. The base station 108 provides services to the wireless terminals, such as a first wireless terminal 102 and a second wireless terminal 104, in the geographic area 106 via a wireless spectrum band. The wireless spectrum band is called the infrastructure band.

In addition to the infrastructure band, a different spectrum band, referred to as non-infrastructure band may also be, and sometimes is, available to be used by the wireless terminals in the same geographic area. Thus wireless terminals (102, 104) can participate in an ad hoc peer to peer communication session using non-infrastructure band. FIG. 2 includes drawing 200 which illustrates the notion of the infrastructure band 202 and the non-infrastructure band 204. The two bands are in some embodiments non-overlapping. In a typical embodiment, the infrastructure band includes a pair of FDD (frequency division duplex) spectrum bands or an unpaired TDD (time division duplex) spectrum band. The non-infrastructure band includes an unpaired spectrum and can be used for ad hoc peer-to-peer communication. In some embodiments, the non-infrastructure band is also used for TDD. In some embodiments, the same infrastructure base station, which provides the service in the infrastructure band, may also provide service in the non-infrastructure band.

In an exemplary embodiment, the infrastructure base station transmits a beacon signal in the infrastructure band. The beacon signal is a special signal that occupies a small fraction of the total minimum transmission units in the available spectrum. In some embodiments, a beacon signal includes a sequence of one or more beacon signal bursts, each beacon signal burst including at least one beacon symbol. In some embodiments, the beacon symbols corresponding to a beacon signal occupy a small fraction, e.g., in some embodiments no more that 0.1%, of the total minimum transmission units in the available spectrum air link resource. A minimum transmission unit is the minimum unit of air link resource to use for communication. In some exemplary frequency division multiplexing systems, e.g., some OFDM systems, a minimum transmission unit is a single tone over a symbol transmission period, sometimes referred to as a tone-symbol. In addition, the average transmission power of the beacon symbols of the beacon signal is much higher, e.g., at least 10 dBs or at least 16 dB higher, than the average transmission power of data and control signals per minimum transmission unit when the terminal transmitter is in an ordinary data session.

In addition, the infrastructure base station, in some embodiments, uses a broadcast channel, including the beacon signal, to send the system information including the frequency (e.g., carrier) location of the non-infrastructure, spectrum band and/or the type of service provided in the band, e.g., TDD (time division duplex) or ad hoc networking.

FIG. 3 illustrates an exemplary ladder diagram 300 of an exemplary method of obtaining and utilizing spectrum information implemented by a wireless terminal in accordance with various embodiments. Drawing 300 includes time axis 301, infrastructure base station 302 and wireless terminal 304.

The wireless terminal 304 knows the frequency location of the infrastructure spectrum band. The wireless terminal 304 first tunes to the infrastructure spectrum band (306) and searches for the beacon signal (308) to find the availability of the infrastructure base station. The infrastructure base station 302 transmits beacon signal 310 which is received and detected (312) by wireless terminal 304. Once the wireless terminal 304 detects the beacon signal (310), the wireless terminal 304 synchronizes (314) itself with the infrastructure base station 302. The infrastructure base station 302 transmits broadcast signals 316, in addition to beacon signals 310. In some embodiments, wireless terminal 304 further receives the broadcast signals 316 and recovers system information from a broadcast channel to obtain the frequency location information of the non-infrastructure spectrum band (318). The wireless terminal 304, in various embodiments, derives timing and/or frequency information from at least one of the broadcast channels and/or the beacon signal (320). The wireless terminal 304 then tunes to the frequency location of the non-infrastructure band to obtain the TDD and/or ad hoc service (322). The wireless terminal 304 uses the timing and/or frequency information derived in step 320 when the terminal 304 obtains the service in the non-infrastructure band (324).

Unlike the infrastructure band, the non-infrastructure band may not, and sometimes does not, have a natural source from which each of the wireless terminals can derive synchronization information. When each of the wireless terminals use the timing and/or frequency information derived from a common source, i.e., the infrastructure base station in the infrastructure spectrum band, the wireless terminals now have a common timing and/or frequency reference. Advantageously this enables synchronization of the terminals in the non-infrastructure band. To elaborate, drawing 400 of FIG. 4 illustrates an example of utilizing timing synchronization information obtained from infrastructure signaling in an associated non-infrastructure band.

The horizontal axis 401 represents time. The infrastructure base station transmits the beacon signal 402 in the infrastructure band. The beacon signal 402 includes a sequence of beacon signal bursts, 404, 406, 408, and so on. Suppose that two wireless terminals derive the timing information from the beacon signal 402, and then tune to the non-infrastructure band, which is used for peer-to-peer ad hoc network.

Either of the two wireless terminals has to be aware of the presence of the other before they can set up a peer-to-peer communication session. In one embodiment, ether wireless terminal transmits or receives a user beacon signal burst in the non-infrastructure band in a time interval, which is a function of the timing of the beacon signal bursts sent by the infrastructure base station.

For example, in FIG. 4, the time interval starts from a time instance that has known time offset 410 from the beginning 412 of a beacon signal burst sent by the infrastructure base station. Either wireless terminal in some embodiments randomly chooses whether to transmit or receive. In the exemplary scenario shown in FIG. 4, the first wireless terminal chooses to transmit, as indicated by exemplary user beacon signal burst 414 transmitted into the non-infrastructure spectrum band, while the second wireless terminal chooses to receive. The second wireless terminal controls its receiver on time interval for beacon monitoring in the non-infrastructure spectrum band such as to include interval 416 corresponding to the first wireless terminal's beacon transmission, and the second wireless terminal detects the user beacon signal sent by the first wireless terminal. The second wireless terminal may, and sometimes does, then start to establish a communication link with the first wireless terminal. However, if both wireless terminals choose to transmit or to receive, then they may not find each other in this time interval. The wireless terminals can probabilistically find each other in subsequent time intervals.

Note that in the absence of the common timing reference, the wireless terminals may have to be in the listening mode in a much longer time interval in order to detect a user beacon signal burst. The common timing reference thus helps the wireless terminals to find each other much more rapidly and in a more power efficient manner.

In another embodiment, the base station additionally transmits the beacon signal in the second spectrum band, so that if the wireless terminal directly tunes to the second spectrum band, the wireless terminal can derive the desired common timing and/or frequency reference from the beacon signal.

FIG. 5 illustrates an exemplary state diagram 500 of receiving paging and being in a peer-to-peer or TDD session implemented in accordance with various embodiments. Operation starts in step 501, where the wireless terminal is powered on and initialized and then proceeds to step 502.

A wireless terminal and the network paging agent, e.g., a server on the network side, have an agreement on when a page for the wireless terminal, if any, will be sent to the wireless terminal via the infrastructure base station. The wireless terminal sets a timer to monitor potential incoming pages (502). In a typical paging system, the wireless terminal may go to a power saving mode until the timer expires. In accordance with a novel feature of various exemplary embodiments, the wireless terminal tunes to the non-infrastructure spectrum band and obtains service (504), e.g., a TDD or peer-to-peer communication service. When the timer expires, the wireless terminal tunes to the infrastructure spectrum band and monitors a paging channel (506). If the terminal is not paged, the wireless terminal may set the timer again for the next page monitoring time (502). Otherwise, the wireless terminal is being paged, needs to process the received page and processes the received page (508).

In some embodiments, there is a common time interval during which each of the wireless terminals or a large subset of the wireless terminals using the non-infrastructure spectrum band suspend the sessions in the non-infrastructure spectrum band and check pages in the infrastructure spectrum band. Advantageously, this synchronized suspension of non-infrastructure sessions helps reduce the wastage of resource in the non-infrastructure band.

FIG. 6 illustrates a flowchart 600 of an exemplary method of operating a wireless terminal to determine data rates corresponding to potential links with alternative nodes, e.g., a base station and a peer wireless terminal, and selecting a node to communicate with in accordance with various embodiments.

A base station transmits a beacon signal. In some embodiments, in the non-infrastructure band, the infrastructure base station transmits a beacon signal, and a wireless terminal also transmits a user beacon signal. Thus, in such an embodiment, a wireless terminal can have its receiver tuned to the non-infrastructure band and receive base station beacon signals and wireless terminal user beacon signals. Different beacon signals, in some embodiments, differentiate from each other by using different beacon tone hopping sequences and/or different timing of beacon bursts. A transmitter e.g., the base station or the wireless terminal, in some embodiments is also used to transmit data/control channels. In accordance with various embodiments, the transmission power of the beacon signal and/or that of the data/control channels are such that from the received beacon signal or signals, a receiver can predict the signal quality of the data/control channels, and/or compare the signal quality from multiple transmitters.

In some embodiments, the transmission power of the base station beacon signal is the same for each base station. In some embodiments, the transmission power of the user beacon signal is the same for each of the wireless terminals transmitting user beacon signals. In some embodiments, the transmission power of base station and user beacons are the same. In some embodiments, the data/control channels are sent at a transmission power, which is a function of the transmission power of the beacon signal. For example, the per minimum transmission unit transmission power of the data channel, at a given coding and modulation rate, is a fixed dB amount, e.g., 10 dBs or 16 dBs, below the transmission power of the beacon signal.

With regard to FIG. 6, operation of the exemplary method starts in step 601, where the wireless terminal is powered on and initialized and proceeds to step 602 for each link being considered in step 602 the wireless terminal receives a beacon signal from a transmitter, e.g., an infrastructure base station transmitter or a wireless terminal transmitter, and then, in step 604 the wireless terminal measures the received power. Operation proceeds from step 604 to step 606. In step 606, the wireless terminal then predicts the received power of user data signals, e.g., a data/control traffic channel, assuming that the wireless terminal is receiving the channel from the transmitter, using the known power relationship between the traffic channel and the beacon signal. In step 608, the wireless terminal further measures the background noise and interference. Then, in step 610, the wireless terminal predicts the signal quality, e.g., signal-to-noise ratio (SNR) of a data session if the wireless terminal is to set up a session with the device, e.g., base station or wireless terminal, corresponding to the transmitter and sees whether the signal quality and thus the data rate of the data session are sufficient. In some cases, the wireless terminal may, and sometimes does, receive beacon signals from multiple transmitters. In step 611, the wireless terminal compares the signal quality from those transmitters considered and selects a proper one with which to communicate, thus selecting the base station or wireless terminal corresponding to the selected transmitter.

FIG. 7 illustrates a ladder diagram 700 of an exemplary method of using beacon and/or broadcast channels to temporarily convert infrastructure spectrum band for non-infrastructure based service implemented in accordance with various embodiments. Unlike some of the other embodiments presented, this exemplary embodiment has an infrastructure band but does not need a fixed non-infrastructure band.

The vertical axis 702 represents time. The infrastructure base station 704 checks (708) whether there is any wireless terminal using the normal service provided by the infrastructure base station, such as normal FDD or TDD service. The normal service is referred to as infrastructure based service. If the answer is no, then the infrastructure base station can convert (710) the infrastructure spectrum band to become a non-infrastructure band, which can be used by non-infrastructure based service, such as peer-to-peer communication service. To do so, the base station sends at least one of a beacon signal (712) and a non-beacon broadcast signal (714) to indicate that the infrastructure band has been converted to non-infrastructure band. Upon the reception of that signal, the wireless terminals, e.g., wireless terminal 706, in the area can start to use non-infrastructure service in the band (716).

At a later time, the infrastructure base station 704 may decide (718) to return the spectrum band to the infrastructure based service. The infrastructure base station in some embodiments does so because of at least one of the following reasons: 1) the infrastructure base station senses that some wireless terminals may need the infrastructure based service; 2) some timer has expired, in which case the timer is used to control the time duration of the infrastructure spectrum band being used as a non-infrastructure band. To do so, the base station 704 sends at least one of a beacon signal (720) and a non-beacon broadcast signal (722) to indicate that the infrastructure band has returned to the infrastructure based service. Upon the reception of that signal, the wireless terminals in the area, e.g., wireless terminal 706, can cease to use non-infrastructure service in the band (724). For example, if a wireless terminal has an on-going peer-to-peer communication session, the wireless terminal shall stop or suspend the session.

FIG. 8 illustrates in drawing 800 two exemplary ad hoc networks (801, 851) in two geographic areas (806, 856), respectively, implemented in accordance with various embodiments.

The ad hoc network 801 in geographic area A 806 includes a number of terminals, such as a first wireless terminal 802 and a second wireless terminal 804, and a special transmitter 808, which transmits a system beacon signal in accordance with the exemplary embodiment. The wireless terminals, in some embodiments, use the system beacon signal as a system reference signal. The special transmitter in some embodiments is coupled to a big network, e.g., the Internet, through a network node 810, e.g., via a wired link. The special transmitter 808, in some embodiments, is also used to have peer-to-peer sessions with a wireless terminal. Alternatively, in some embodiments the transmitter may be, and sometimes is a standalone unit.

The ad hoc network 851 in geographic area B 856 includes a number of terminals, such as a third wireless terminal 852 and a fourth wireless terminal 854, and a special transmitter 858, which transmits a system beacon signal in accordance with the exemplary embodiment. The special transmitter in some embodiments is coupled to a big network, e.g., the Internet, through a network node 860, e.g., via a wired link.

In this exemplary embodiment, the spectrum availability is a function of the environment. Here, infrastructure spectrum bands may not exist. For example, drawing 900 of FIG. 9 shows exemplary spectrum bands available in geographic area A 806 and in geographic area B 856. Those spectrum bands are non-infrastructure.

The horizontal axis 905 represents frequency. The upper portion 901 of the FIG. 9 shows that there are two spectrum bands, 902 and 904, available for use in the ad hoc network 801 in geographic area A 806. The lower portion 903 of FIG. 9 shows that there are two spectrum bands, 906 and 908, available for use in the ad hoc network 851 in geographic area B 856. In the exemplary scenario shown in FIG. 9, the spectrum bands 904 and 908 are identical. In other words, part of the spectrum bands available in area A and area B (904 and 908) are the same, while the rest (902 and 906) are different.

One reason that a different set of spectrum bands are available in a different area is that a spectrum band may have been allocated to other services in some geographic area but can be made available in another area. When a wireless terminal moves into area A or area B, the wireless terminal needs to first figure out which spectrum bands are available for use, so that the wireless terminal does not cause interference or disruption to existing services.

To help the wireless terminal to figure out the spectrum availability in a given area, in accordance with a feature of some embodiments, a special transmitter transmits a system beacon signal in each of the spectrum bands that are available for use in the vicinity of the geographical area in which the special transmitter is located. The beacon signal is a special signal that occupies a small fraction of the total minimum transmission units in the available spectrum. In some embodiments, the beacon symbols of the beacon signal occupy no more than 0.1% of the total minimum transmission units in the available spectrum air link resource. A minimum transmission unit is the minimum unit of resource to use for communication. In some exemplary frequency division multiplexing systems, e.g., some OFDM systems, a minimum transmission unit is a single tone over a symbol transmission period, sometimes referred to as an OFDM tone-symbol. In addition, the transmission power of the beacon symbols per minimum transmission unit is much higher, e.g., in some embodiments at least 10 dB higher, than the average transmission power of data and control signals per minimum transmission unit when the transmitter is in an ordinary data session. In some such embodiments, the transmission power of the beacon signal's beacon symbols per minimum transmission unit is at least 16 dBs higher than the average transmission power of data and control signals per minimum transmission unit then the transmitter is in an ordinary data session.

Drawing 1000 of FIG. 10 illustrates exemplary system beacon signals transmitted in exemplary ad hoc networks (801, 851) in two different geographic areas (806, 856), respectively. The upper portion 1002 illustrates the system beacon signal transmitted by the special transmitter 808 in area A 806 and the lower portion 1004 illustrates the system beacon signal transmitted by the special transmitter 858 in area B 856.

In either the upper or the lower portion (1002, 1004), the horizontal axis 1006 represents frequency and the vertical axis 1008 represents time.

Recall from FIG. 9 that spectrum bands 902 and 904 are available in area A 806. The upper portion 1002 of FIG. 10 shows that the special transmitter 808 transmits the system beacon signal burst 1010 including beacon symbol(s) 1012 at time t1 1014 in spectrum band 902, and transmits the system beacon signal burst 1016 including beacon symbol(s) 1018 at time t2 1020 in spectrum band 904. The transmitter 808 then repeats the above procedure and transmits the system beacon signal burst 1022 including beacon symbol(s) 1024 at time t3 1026 in spectrum band 902 and transmits the system beacon signal burst 1028 including beacon symbol(s) 1030 at time t4 1032 in spectrum band 904, and so on. In some embodiments, the beacon signal bursts 1010 and 1022 are identical, e.g., the beacon symbols occupy the same positions in a beacon burst. In some embodiments, the beacon signal bursts 1010, 1022 vary, e.g., the positions of the beacon symbols(s) change in accordance with a predetermined hopping sequence being implemented by beacon transmitter 808. In some the beacon signal bursts 1016 and 1028 are identical. In some embodiments the beacon signal bursts 1016 and 1028 vary, e.g., in accordance with a predetermined hopping sequence being implemented by beacon transmitter 808. In some embodiments, the beacon signal bursts 1010 and 1016 are similar, e.g., the beacon symbols occupy the same relative positions in the beacon burst.

Recall from FIG. 9 that spectrum bands 906 and 908 are available in area B 856. The lower portion 1004 of FIG. 10 shows that the special transmitter 858 transmits the system beacon signal burst 1034 including beacon symbol(s) 1036 at time t5 1038 in spectrum band 906 and transmits the system beacon signal burst 1040 including beacon symbol(s) 1042 at time t6 1044 in spectrum band 908. The transmitter 858 then repeats the above procedure and transmits the system beacon signal burst 1046 including beacon symbol(s) 1048 at time t7 1050 in spectrum band 906 and transmits the system beacon signal burst 1052 including beacon symbol(s) 1054 at time t8 1056 in spectrum band 908, and so on.

In an exemplary embodiment, at a given time, a special transmitter transmits at most one beacon signal burst in a spectrum band. The special transmitter hops across each of the available spectrum bands, successively from one spectrum band to another, and transmits the beacon signal burst in each band at a given time. For example, in the embodiment shown in FIG. 10, times t1 1014, t2 1020, t3 1026, t4 1032 do not overlap with each other. However, it is also possible that in other embodiments the transmitter may, and sometimes does, simultaneously transmit multiple beacon signals, each in a different spectrum band.

In the example of drawing 1000 of FIG. 10, with respect to the transmitter 808 in area A, t4 >t3 >t2 >t1, and with respect to the transmitter 858 in area B, t8 >t7 >t6 >t5. However, the drawing does not intend to show that a timing relationship between t5 and t4 exists such that t5 is necessarily greater than t4. For example, the range of time including (t1, t2, t3, t4) and the range of time including (t5, t6, t7, t8) may, and sometimes does, at least partially overlap. In some embodiments, the two transmitters (808, 858) operate independently from one another and are not intentionally timing synchronized. In some embodiments, the two transmitters (808, 858) have timing structures which are coordinated, e.g., synchronized with respect to one another.

FIG. 11 provides a detailed illustration of an exemplary wireless terminal 1100 implemented in accordance with the present invention. The exemplary terminal 1100, depicted in FIG. 11, is a detailed representation of an apparatus that may be used as any one of terminals 102 and 104 depicted in FIG. 1. In the FIG. 11 embodiment, the wireless terminal 1100 includes a processor 1104, a wireless communication interface module 1130, a user input/output interface 1140 and memory 1110 coupled together by bus 1106. Accordingly, via bus 1106 the various components of the wireless terminal 1100 can exchange information, signals and data. The components 1104, 1106, 1110, 1130, 1140 of the wireless terminal 1100 are located inside a housing 1102.

The wireless communication interface 1130 provides a mechanism by which the internal components of the wireless terminal 1100 can send and receive signals to/from external devices and another terminal. The wireless communication interface 1130 includes, e.g., a receiver module 1132 and a transmitter module 1134, which are connected with a duplexer 1138 with an antenna 1136 used for coupling the wireless terminal 1100 to other terminals, e.g., via wireless communications channels.

The exemplary wireless terminal 1100 also includes a user input device 1142, e.g., keypad, and a user output device 1144, e.g., display, which are coupled to bus 1106 via the user input/output interface 1140. Thus, user input/output devices 1142, 1144 can exchange information, signals and data with other components of the terminal 1100 via user input/output interface 1140 and bus 1106. The user input/output interface 1140 and associated devices 1142, 1144 provide a mechanism by which a user can operate the wireless terminal 1100 to accomplish various tasks. In particular, the user input device 1142 and user output device 1144 provided the functionality that allows a user to control the wireless terminal 1100 and applications, e.g., modules, programs routines and/or functions, that execute in the memory 1110 of the wireless terminal 1100.

The processor 1104 under control of various modules, e.g., routines, included in memory 1110 controls operation of the wireless terminal 1100 to perform various signaling and processing. The modules included in memory 1110 are executed on startup or as called by other modules. Modules may exchange data, information, and signals when executed. Modules may also share data and information when executed. In the FIG. 11 embodiment, the memory 1110 of wireless terminal 1100 includes a signaling/control module 1112 and signaling/control data 1114.

The signaling/control module 1112 controls processing relating to receiving and sending signals, e.g., messages, for management of state information storage, retrieval, and processing. Signaling/control data 1114 includes state information, e.g., parameters, status and/or other information relating to operation of the wireless terminal. In particular, the signaling/control data 1114 includes various configuration information 1116, e.g., the page monitoring interval, the frequency location of infrastructure spectrum band and non-infrastructure spectrum band, the timing and/or frequency reference information of the beacon signal received from the infrastructure base station, and the power relationship between the beacon signal and the data/control traffic channel. The module 1112 may, and sometimes does, access and/or modify the data 1114, e.g., update the configuration information 1116. The module 1112 also includes a module 1113 for receiving system info and timing info on non-infrastructure band from infrastructure base station; module 1115 for using system and timing info in non-infrastructure band; module 1117 for suspending session in non-infrastructure band and monitoring pages in infrastructure band; and module 1119 for predicting signal quality of a data session from received beacon signal power from a transmitter.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is a flowchart 1200 of an exemplary method of operating a wireless terminal to communicate with another communications device in accordance with various embodiments. Operation starts in step 1202, where the wireless terminal is powered on and initialized and proceeds to step 1204. In step 1204, the wireless terminal receives a first signal from a first communications band, said first signal being from a first communications device which broadcasts on a recurring basis, said first communications device and said another communications device being different communications devices. Operation proceeds from step 1204 to step 1206.

In step 1206, the wireless terminal determines, based on the first signal, a first time interval to be used for transmitting a second signal to said another communications device. Then, in step 1208, the wireless terminal determines based on the first signal a second time interval to be used for receiving signals from devices other than the first communications device. Operation proceeds from step 1208 to step 1210.

In step 1210, the wireless terminal derives frequency information from the received first signal. Step 1210 includes sub-step 1211 in which the wireless terminal determines a second communications band based on the received first signal. Operation proceeds from step 1210 to step 1212 in which the wireless terminal derives a parameter form the received first signal. Operation proceeds from step 1212 to step 1214 in which the wireless terminal receives another signal from the first communications device, and then in step 1216 the wireless terminal derives a second parameter from another signal received from said first communications device. Operation proceeds from step 1216 to step 1218.

In step 1218, the wireless terminal determines at least one transmit frequency to be used for transmitting said second signal from the derived frequency information. Operations proceed from step 1218 via connecting node A 1220 to step 1222 of FIG. 12B.

In step 1222, the wireless terminal generates a second signal as a function of one of device identifier corresponding to said wireless terminal and a user identifier corresponding to a user of said wireless terminal. Then, in step 1224, the wireless communications device transmits said second signal to said another communications device during said first time interval. Step 1224 includes sub-step 1225 in which the wireless terminal transmits said second signal into said second communications band, which is different from said first communications band. Operation proceeds from step 1224 to step 1226.

In step 1226, the wireless terminal determines at least one additional transit time as a function of said parameter derived from said first signal. Step 1226 includes sub-step 1227, in which the wireless terminal uses a time hopping function which uses said parameter and/or said second parameter as input parameters. Operation proceeds from step 1226 to step 1228.

In step 1228, the wireless terminal establishes a peer to peer communications session with said another device using timing synchronization information derived from said first signal. Then, in step 1230, the wireless terminal exchanges user data as part of said peer to peer communications session, said user data including at least one of voice data, other audio data, image data, text data and file data, said peer to peer communications session being conducted directly between said wireless terminal and said another device over a direct airlink.

In some embodiments the first and second communications bands are non-overlapping. In various embodiments, the first and second communications bands are partially overlapping. In some embodiments, the second signal includes a beacon signal burst, e.g., an OFDM beacon signal burst including at least one beacon symbol. In some embodiments, the second signal is a pseudo noise sequence signal transmitted over the frequency spectrum of the second frequency band. In some embodiments both the first and second signals are OFDM signals. In some embodiments, both the first and second signals are CDMA signals. In some embodiments, both the first and second signals are GSM signals. In some embodiments the first signal is a GSM signal and the second signal is an OFDM signal. In some embodiments, the first signal is a CDMA signal and the second signal is an OFDM signal. In various embodiments, the first signal is a satellite broadcast signal, e.g., a GPS signal, a timing reference signal, a reference signal obtained from a geostationary satellite, a signal from a satellite TV and/or radio broadcast, etc., and the second signal is a terrestrial broadcast signal. The terrestrial broadcast signal is, e.g., from a fixed position base station, from a fixed position special transmitter, e.g., a beacon transmitter, or from a movable transmitter temporarily stationed at a fixed site to provide a reference such as a beacon signal, to be available for use by mobile nodes in the vicinity for a peer to peer network. In some embodiments, the first signal is received from a terrestrial cellular network and the wireless terminal is a mobile handset.

One exemplary embodiment will now be described corresponding to flowchart 1200 of FIG. 12. The wireless terminal is a first mobile node, and the another communications device is a second mobile node which participates in a peer to peer communications session with the first mobile node. The first communications device is a device such as a base station, special beacon transmitter, satellite, etc., which provides reference information to be used by the wireless terminal and another communications device. The first signal is an OFDM beacon signal burst including at least one beacon symbol, e.g., a high energy tone, transmitted into the first frequency band. The another signal is, e.g., a non-beacon broadcast signal transmitted from the first communications device. Reference timing information is derived from the first signal and used in determining a time for the wireless terminal to receive beacon signals from other wireless terminals, e.g., peers, and in determining a time to transmit its own user beacon signal. The second signal is an OFDM user beacon signal burst including at least one beacon symbol, which is generated as a function of an identifier associated with the wireless terminal or wireless terminal user. From the received first signal the wireless terminal derives the second communications band, which is the communications band to be used for peer to peer communications, which includes transmit frequencies of the user beacon to be generated by the wireless terminal. In this embodiment, the first and second communications bands are non-overlapping. Thus the wireless terminal's user beacon and peer to peer user data are communicated into the same band, the second communications band. First and second parameters are input control parameters used in a time hopping sequence associated with user beacon signals generated and transmitted by the wireless terminal. For example, one of first and second parameters may provide an indication or notion of time and the other may provide an identifier associated with the transmitter. The wireless terminal time hops the relative position of the beacon burst within a time window from one beacon burst to the next, in accordance with the hopping sequence using the input control parameters.

FIG. 13 is a drawing of an exemplary wireless terminal 2300, e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 2300 includes a receiver module 2302, a transmission module 2304, a coupling module 2303, a processor 2306, user I/O devices 2308, a power supply module 2310 and memory 2312 coupled together via a bus 2314 over which the various elements may interchange data and information. Memory 2312 includes routines 2316 and data/information 2318. The processor 2306, e.g., a CPU, executes the routines and uses data/information 2318 in memory 2312 to control the operation of the wireless terminal 2300 and implement methods.

Coupling module 2303, e.g., a duplex module, couples the receiver module 2302 to antenna 2305 and the transmission module 2304 to antenna 2305. Power supply module 2312, which includes a battery 2311, is used to power up the various components of the wireless terminal. Power is distributed from the power supply module 2310 to the various components (2302, 2303, 2304, 2306, 2308, 2312), via a power bus 2309. User I/O devices 2308 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 2308 are used for operations including inputting user data, accessing output user data, and controlling at least some functions and operations of the wireless terminal, e.g., initiating a peer to peer communications session.

Routines 2316 include a transmission interval timing determination module 2320, a receive interval timing determination module 2322, a transmission band control module 2324, a peer to peer communications band determination module 2326, a second signal generation module 2328, an additional transmit time determination module 2330, a peer to peer communications establishment module 2332, a peer to peer sessions management module 2334, a frequency information recovery module 2336, and a transmission frequency determination module 2338. Data/information 2318 includes a received 1^(st) signal 2340, a determined first time interval 2342, 1^(st) frequency band information 2358, a second signal 2344, a determined 2^(nd) time interval 2346, 2^(nd) frequency band information 2360, device identification information 2362, user identification information 2364, time hopping function information 2348, a first time hopping function input parameter 2350, a second time hopping function input parameter 2352, a plurality of transmit times corresponding to beacon burst transmissions (transmit time for beacon burst 1 2354, . . . , transmit time for beacon burst n 2356), conveyed frequency information 2366, and peer to peer session information 2368. The peer to peer session information 2368 includes peer identification information 2370, received user data 2372, user data to be transmitted 2374, and transmit frequency information 2376.

Receiver module 2302, e.g., a receiver, receives a first signal from a first communication band, said first signal being from a first communications device which broadcasts on a recurring basis. The first communications device is a different communications device than the communications device with which wireless terminal 2300 has a communications session. Information representing the received 1^(st) signal 2340 is stored in memory 2312, and 1^(st) frequency band information 2358 identifies the frequency band to which the receiver module is tuned when receiving the 1^(st) signal. The 1^(st) signal is, e.g., a broadcast signal used to obtain a timing reference by the wireless terminal 2300. Receiver module 2302 also receives signals from other communication devices, e.g., a part of communications sessions such as peer to peer communications sessions. Some of the received signals include user data 2372. In some embodiments, receiver module 2302 supports a plurality of signal technologies, e.g., the first signal which is used as a reference may be and sometimes is a different technology than the technology used for peer to peer communications sessions.

Transmission module 2304, e.g., an OFDM transmitter, is used for transmitting a second signal 2344 to a communications device, e.g., a peer wireless terminal, during a determined 1^(st) time interval 2342. In some embodiments, the second signal 2344 includes a beacon signal burst, e.g., an OFDM beacon signal burst including at least one beacon symbol. Transmission module 2304 also transmits user data 2344, as part of a peer to peer communications session using transmit frequency information 2376.

Transmission interval timing determination module 2322 determines, based on the received 1^(st) signal 2340, a first time interval 2342 to be used for transmitting 2^(nd) signal 2344, e.g., a WT 2300 beacon signal burst, to another communications device, e.g., a peer wireless terminal. Receive interval timing determination module 2322 determines, based on the received 1^(st) signal 2340, a 2^(nd) time interval 2346 to be used for receiving signals from devices other than the device which transmitted the 1^(st) signal. In some embodiments, the 2^(nd) time interval is a time interval in which wireless terminal 2300 is to receive and monitor for beacon signals from another communications device, e.g., peer wireless terminal.

Transmission band control module 2324 controls the wireless terminal 2300 to transmit the 2^(nd) signal 2344, e.g., WTs 2300's beacon signal burst, in a second communications band identified by 2^(nd) frequency band information 2360. In some embodiments, the 2^(nd) frequency band is different from the 1^(st) frequency band. For example, the wireless terminal 2300 receives a broadcast signal used for timing synchronization in a 1^(st) band and transmits its user beacon in a 2^(nd) frequency band, which is a different band.

Peer to peer communications band determination module 2326 determines, prior to transmitting the 2^(nd) signal 2344 the 2^(nd) communication band based on the 1^(st) received communications signal 2340. Thus peer to peer communications band determination module 2326 determines 2^(nd) frequency band information 2360. In some embodiments, the 1^(st) and 2^(nd) frequency bands are non-overlapping frequency bands. In some embodiments, the 1^(st) and 2^(nd) frequency bands are partially overlapping frequency bands.

Second signal generation module 2328, generates 2^(nd) signal 2344, prior to transmitting the second signal as a function of one of a device identifier 2362 corresponding to the wireless terminal and a user identifier 2364 corresponding to a user of wireless terminal 2300. In some embodiments, second signal generation module 2328 generates signaling including beacon signal bursts, e.g., OFDM beacon signal bursts including at least one beacon symbol. In some embodiments, the second signal is a pseudo noise sequence transmitted over the second frequency band.

Additional transmit time determination module 2330 determines at least one additional transmit time as a function of a parameter derived from the 1^(st) signal, e.g., time hopping function input parameter 1 2350. The additional transmit time determination module 2330 uses a time hopping function which uses parameter 2350 as an input. Time hopping function information 2348 includes, e.g., information defining the time hopping sequence. In some embodiments, the time hopping function uses a second input parameter 2352 derived from another signal received from the communications device which transmitted the 1^(st) broadcast signal. For example, the another signal may be, and sometimes is, a non-beacon broadcast signal communicating the 2^(nd) input parameter. The another signal may be, and sometimes is, another beacon signal burst.

Peer to peer communications establishment module 2332 is used to establish a peer to peer communications session with another device, e.g., a peer node, using timing synchronization information derived from the received 1^(st) signal 2340.

Peer to peer session management module 2334 controls the exchange of used data including at least one of voice data, text data, and image data, said peer to peer communications session being conducted directly between the wireless terminal and another device, e.g., peer wireless terminal, over a direct air link.

Frequency information recovery module 2336 recovers conveyed frequency information 2366 from the received 1^(st) signal 2340, prior to transmitting the second signal 2344, deriving frequency information from the received 1^(st) signal 2340. For example, the 1^(st) signal conveyed information identifying the 2^(nd) frequency band, the 2^(nd) frequency band to be used by wireless terminal 2300 for transmitting its user beacon signal and for peer to peer user data communications.

Transmission frequency determination module 2338 determines at least one transmit frequency to be used for transmitting the second signal from derived frequency information. Information including in 2376 is an output of module 2338. Transmit information 2376 includes e.g., frequency band information and/or individual tone identification information. In some embodiments, transmit frequency information identifies OFDM tones used to convey beacon symbols of beacon signal bursts to be transmitted by wireless terminal 2300. In some such embodiments, beacon symbol tones are tone hopped from one burst to another in a sequence of bursts in accordance with a tone hopping sequence.

In some embodiments, both the first and second signals are OFDM signals. In some embodiments, the first signal is a GSM signal and the second signal is an OFDM signal. In some embodiments, the first signal is a CDMA signal and the second signal is an OFDM signal. In some embodiments, the first signal is a satellite broadcast signal and the second signal is a terrestrial broadcast signal. In some embodiments, the first signal is received from a terrestrial cellular network and the wireless terminal is a mobile handset.

FIG. 14 is a drawing of a flowchart 1300 of an exemplary method of operating a wireless terminal which supports both peer to peer communications and communications with a base station in accordance with various embodiments. Operation starts in step 1302, where the wireless terminal is powered on and initialized and proceeds to step 1304. In step 1304, the wireless terminal receives a first signal from a first communications band, the first signal being from a base station. Operation proceeds from step 1304 to step 1306. In step 1306, the wireless terminal determines the frequency of a second communications band from the first signal, and in step 1308, the wireless terminal determines an interval of time during which the wireless terminal is to monitor for a second signal in the second communications band, the determination of the time interval being based on information communicated by the first signal, e.g., a time reference communicated. Operation proceeds from step 1308 to step 1310.

In step 1310, the wireless terminal determines from said first signal link the quality of a first link between said base station and said wireless terminal, and in step 1312, the wireless terminal predicts a first data throughput to the base station based on the first determined link quality. Step 1312 includes sub-step 1314, in which the wireless terminal uses maximum transmission power information in the first link quality determination. The maximum transmission power information includes, e.g., at least one of a government restriction on maximum transmission power and device output capability. Operation proceeds from step 1312 to step 1316.

In step 1316, the wireless terminal monitors during said determined time interval to receive said second signal, and then in step 1318, the wireless terminal receives said second signal from the second communications band, said second communications band being different from the first communications band, said second signal being from a peer wireless terminal. In some embodiments, the first and second signal each include at least one beacon signal burst.

Operation proceeds from step 1318 to step 1320. In step 1320, the wireless terminal predicts a second data throughput to the peer wireless terminal based on the second determined link quality. Step 1320 includes sub-step 1322 in which the wireless terminal uses maximum transmission power information in the second link quality determination. The maximum transmission power information includes, e.g., at least one of a government restriction on maximum transmission power and device output capability. Operation proceeds from step 1320 to step 1324, in which the wireless terminal selects between said first and second links for a communications session based on the determined quality of the first and second links. Step 1324 includes alternative sub-steps 1326, 1328, and 1330.

In alternative sub-step 1326, the wireless terminal selects the one of the first and second links having a higher data throughput. In alternative sub-step 1328, the wireless terminal performs the selection as a function of energy required to maintain said first and second links, said selecting including selecting the one of the first and second links satisfying a link quality requirement and also requiring the least amount of energy to maintain. In alternative sub-step 1330, the wireless terminal performs selection as a function of a lest cost routing determination that takes into consideration an economic cost associated with using individual ones of said first and second links.

FIG. 15 is a drawing of an exemplary wireless terminal 2400, e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 2400 supports both peer to peer communications and communications via a base station. Exemplary wireless terminal 2400 includes a receiver module 2402, a transmitter module 2404, a processor 2406, user I/O devices 2408 a memory 2410 coupled together via a bus 2412 over which the various elements may exchange data and information. Memory 2410 includes routines 2414 and data/information 2416. The processor 2406, e.g., a CPU, executes the routines 2414 and uses the data/information 2416 in memory 2410 to control the operation of the wireless terminal 2400 and implement methods.

Receiver module 2402, e.g., an OFDM receiver, is coupled to receive antenna 2403 via which the wireless terminal 2400 receives signals from base stations and other wireless terminals. Transmitter module 2404, e.g., an OFDM transmitter, is coupled to transmit antenna 2405 via which the wireless terminal 2400 transmits signals to base stations and to other wireless terminals. In some embodiments, the same antenna is used for both the receiver and transmitter modules (2402, 2404).

User I/O devices 2408 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 2408 are used for operations including inputting user data, accessing output user data, and controlling at least some functions and operations of the wireless terminal, e.g., initiating a communications session.

Routines 2414 include a communications routine 2418 and wireless terminal control routines 2420. The communications routine 2418 implements the various communications protocols used by the wireless terminal 2400. The wireless terminal control routines 2420 include a base station link quality determination module 2422, a peer to peer link quality determination module 2424, a link selection module 2426, a beacon burst processing module 2428, a user data recovery module 2430, a first data throughput determination module 2432, a second data throughput determination module 2434, a power requirement estimation module 2436, a routine cost determination module 2438, a frequency band determination module 2440, a monitor interval determination module 2442, and a peer to peer signal monitoring module 2444.

Data/information 2416 includes a received 1^(st) signal 2446, 1^(st) frequency band information 2448, base station identification information corresponding to the base station which transmitted the 1^(st) signal 2450, recovered 1^(st) link information 2452, predicted 1^(st) link data throughput 2454, estimated amount of energy required to maintain 1^(st) link 2456, routing cost determination associated with 1^(st) link 2458, determined 1^(st) link quality 2460, received 2^(nd) signal 2462, 2^(nd) frequency band information 2464, peer wireless terminal identification information corresponding to the peer wireless terminal which transmitted the 2^(nd) signal 2465, recovered 2^(nd) link information 2466, predicated 2nd link data throughput 2468, estimated amount of energy required to maintain 2^(nd) link 2470, routing cost determination associated with 2^(nd) link 2472, determined 2^(nd) link quality 2474, selected link information 2476, recovered user data 2478, stored maximum transmission power information 2480, stored link quality requirement information 2486, and determined interval of time to monitor for second signals 2488. Stored maximum transmission power information 2480 includes government restriction information 2482 and device output capability information 2484.

Receiver module 2402 receives a 1^(st) signal from a 1^(st) communication band, the first signal being from a base station. Received 1^(st) signal 2446 includes information representing the 1^(st) signal which was received in the band identified by 1^(st) frequency band information 2448 and was transmitted by the base station identified in information 2450. Receiver module 2402 also receives a second signal from a second communications band which is different from the first communications band, said second signal being from a peer wireless terminal. Received 2^(nd) signal 2462 includes information representing the 2^(nd) signal which was received in the band identified by 2^(nd) frequency band information 2464 and was transmitted by the peer wireless terminal identified in information 2465. In some embodiments, the first and second signals each include at least one beacon signal burst, e.g., a OFDM beacon signal burst including at least one beacon symbol.

Base station link quality determination module 2422 determines, from the first signal, link quality of a first link between a base station which transmitted the first signal and the wireless terminal 2400, and determined 1^(st) link quality 2460 is an output of module 2422. Peer to peer link quality determination module 2424 determines, from the second signal, link quality of a second link between a peer wireless terminal which transmitted the second signal and the wireless terminal 2400, and determined 2^(nd) link quality 2474 is an output of module 2424.

Link selection module 2426 selects between 1^(st) and 2^(nd) links for a communications session, based on the determined quality of the first and second links. Determined 1^(st) link quality 2460 and determined 2^(nd) link quality 2474 are inputs to link selection module 2426 and selected link information 2476 is an output of link selection module 2426 which identifies the selected link.

Beacon burst processing a module 2428 recovers link information from beacon signal bursts (recovered 1^(st) link information 2452 corresponding to 1^(st) signal, recovered 2^(nd) link information 2466 corresponding to 2^(nd) signal). User data recovery module 2430 recovers user data 2478 from non-beacon signals used to communicate user data as part of a communications session. At some times the recovered user data 2478 is from a peer to peer communication session, while at other times the recovered user data is from a communications session in which the user data is relayed through a base station serving as an access node.

First data throughput determination module 2432 predicts a first data throughput 2454 to the base station based on the first determined link quality 2460. Second data throughput determination module 2434 predicts a second data throughput 2468 to the peer wireless terminal based on the second determined link quality 2474. Link selection module 2426 includes a throughput based selection module for selecting the one of the first and second links having the higher data throughput. First data throughput determination module 2432 uses the stored maximum transmission power information 2480 in predicting the first data throughput 2454. Second data throughput determination module 2434 uses the stored maximum transmission power information 2480 in predicting the second data throughput 2468.

Power requirement estimation module 2436 estimates the amount of energy required to maintain the 1^(st) and 2^(nd) links (estimated amount of energy required to maintain 1^(st) link 2456, estimated amount of energy required to maintain 2^(nd) link 2470). Link selection module 2426 also performs selection between first and second links for a communications session as a function of energy required to maintain first and second links, said selecting including selecting the one of the 1^(st) and 2^(nd) links satisfying a link quality requirement 2486 and also requiring the least amount of energy to maintain.

Routing cost determination module 2438 performs a routing cost determination that takes into consideration economic costs associated with using individual ones of the first and second links. Routing cost determination associated with 1^(st) link 2458 and routing cost determination associated with 2^(nd) link 2472 are outputs of module 2438. Link selection module 2426 also performs selection between first and second links as a function of least cost routing determination, e.g., using info (2458, 2472) that takes into consideration economic costs associated with individual ones of the first and second links.

Frequency band determination module 2440 determines, prior to receiving the second signal, the frequency band of the second signal from the first signal. Thus a base station identifies the frequency band to be used for peer to peer communications in its vicinity. Monitor interval determination module 2442 determines an interval of time during which said wireless terminal 2400 is to monitor for second signals 2488, e.g., a time interval for wireless terminal 2400 to search for user beacon signals from peer nodes. Peer to peer signal monitoring module 2444 monitors for a signal from a peer wireless terminal during the interval identified to receive second signals, e.g., peer to peer signal monitoring module 2444 monitors for user beacon signal bursts from peer nodes.

In some embodiments, the selection module 2426 changes selection criteria and/or re-weights selection criteria as a function of base station identification information, peer identification information, priority information, type of information anticipated to be communicated, wireless terminal 2400 current conditions, and/or latency requirement. For example, selection module 2426, in some embodiments, heavily weights the selection as a function of energy requirements, when a low battery power condition is detected in wireless terminal 2400. As another example, selection module 2426 heavily weights the selection based on predicted data throughput when a large amount of time critical data is anticipated to be communicated.

FIG. 16 is a drawing of a flowchart 1400 of an exemplary method of operating a base station in accordance with various embodiments. Operation starts in step 1402, where the base station is powered on and initialized and proceeds to step 1404. In step 1404, the base station transmits a beacon signal, said beacon signal including at least one beacon signal burst, said beacon signal conveying information about a peer to peer frequency band, e.g., a peer to peer frequency band which is available for use in the vicinity of the base station. Step 1404 includes sub-step 1406. In sub-step 1406, the base station transmits the beacon signal into a first communications band, said beacon signal conveyed information indicating a second frequency band which is used as said peer to peer frequency band, said second frequency band being different from said first frequency band. Operation proceeds from step 1404 to step 1408.

In step 1408, the base station transmits a second beacon signal into the first communications band, said second beacon signal providing timing synchronization information to a plurality of wireless terminals using the base station as an access node. Operation proceeds from step 1408 to step 1410.

In step 1410, the base station receives data from at least some of said plurality of wireless terminals using said base station as an access node for communication through said access node, and in step 1412, the base station transmits user data to at least some of said plurality of wireless terminals using said base station as an access node using the first frequency band. Operation proceeds from step 1412 to step 1404.

In some embodiments, the first frequency band is used in a time division multiplexed manner, and said step of receiving data (1410) receives data in the first communications band during a first time period and said step of transmitting user data into the first frequency band (1412) is performed during a second time period which is different from said first time period. In some other embodiments, the base station uses the first frequency band for transmitting signals including said beacon signal, said second beacon signal and said user data signals, while a third communications band is used for receiving user data signals from wireless terminals using the base station as an access point. In some such embodiments, the first, second and third communications bands are different and non-overlapping. In some such embodiments, the base station transmits and receives user data concurrently.

In some embodiments, the average, base station transmitted power into the second communications band over a 1 minute time period is less than 1/1000 the average base station transmitted power into the first frequency band over the same 1 minute interval. In some such embodiments, the base station does not transmit any power into the second frequency band.

In another embodiment, which is a variation of embodiments described with respect to flowchart 1400, the base station transmits its access node beacon signal and user data into the first frequency band, and transmits a beacon signal for peer to peer communications into the second frequency band, the second frequency band being used for peer to peer communications, but the base station does not transmit any user data into the second frequency band. In some such embodiments, the average base station transmitted power into the second communications band over a 1 minute time period is less than 1/1000 the average base station transmitted power into the first frequency baud over the same 1 minute interval.

In still another embodiment, which is a variation with respect to flowchart 1400, the base station transmits both its access node beacon signal and its peer to peer node beacon signal in a first frequency band used for beacon signals. In addition, the base station transmits user data intended for wireless terminals using the base station as an access node into a second frequency band; and the base station refrains from transmitting user data into a third frequency band which is utilized for peer to peer communications, wherein said first, second and third communications bands are non-overlapping.

FIG. 17 is a drawing of an exemplary base station 2500 in accordance with various embodiments. Exemplary base station 2500 includes a receiver module 2502, with associated antenna 2501, a transmission module 2504, with associated transmitter antenna 2503, a processor 2506, and I/O interface 2508, and memory 2510 coupled together via a bus 2512 over which the various elements interchange data and information. Memory includes routines 2514 and data/information 2516. The processor 2506, e.g., a CPU, executes the routines 2514 and uses the data/information 2516 in memory 2510 to control the operation of the base station 2500 and implement methods, e.g., the method of FIG. 16.

Routines 2514 include a beacon signal generation module 2518, a frequency band control module 2520, a user data transmission control module 2522, a transmission power control module 2524, and an access node beacon signal generation module 2526. Data/information 2516 includes stored peer to peer beacon signal characteristic information 2528, stored access node beacon signal characteristic information 2534, peer to peer beacon signal transmission band information 2556, access node beacon signal transmission band information 2558, peer to peer communications band information 2560, base station access node band information 2562, timing information 2564, transmission power information 2566, and wireless terminal data/information 2540 corresponding to wireless terminals using the base station 2500 as an access node.

Stored peer to peer beacon signal characteristic information 2528 includes one or more sets of beacon burst information (beacon burst 1 information 2530, . . . , beacon burst N information 2532). Stored access node beacon signal characteristic information 2534 includes one or more sets of beacon burst information (beacon burst 1 information 2536, . . . , beacon burst N information 2538).

WTs data/information 2540 corresponding to WTs using the base station as an access node includes a plurality of sets of information (WT 1 data/information 2542, . . . , WT n data/information 2544). WT 1 data/information 2542 includes received user data 2546, user data to be transmitted 2548, a base station assigned wireless terminal identifier 2550, state information 2552, and communications session information 2554.

Receiver module 2502, e.g., an OFDM receiver, receives uplink signals from wireless terminals using the base station 2500 as an access node. The received signals include user data signals, e.g., traffic channel signals, from a plurality of wireless terminals using base station 2500 as an access node for communication through the access node. Received user data 2546 corresponding to WT 1 represents user data obtained from received signals from one exemplary wireless terminal using base station 2500 as an access node.

Transmitter module 2504, e.g., an OFDM transmitter, transmits signals to wireless terminals in its vicinity. The transmitted signals include a generated beacon signal intended to support peer to peer communications in its vicinity. The generated beacon signal includes at least one beacon signal burst and conveys information about a peer to peer frequency band. The transmitted signals also include a generated second beacon signal intended to support access node operations, the generated second beacon signal providing timing synchronization information to a plurality of wireless terminals using the base station as an access node. In some embodiments, the generated beacon signal conveying peer to peer frequency band information and the generated second beacon signal communicating access node timing synchronization information are transmitted into the same frequency band. The transmitter 2504 also transmits control data and user data to wireless terminals using the base station as an attachment point. User data to be transmitted 2548, corresponding to wireless terminal 1, is an example of user data that is transmitted by the base station 2500, e.g., in downlink traffic channel segments, to a wireless terminal using the base station as an access node. User data includes, e.g., voice, image, text, and/or file data.

In some embodiments, receiving data includes receiving data from wireless terminals using the base station as an access node in a first frequency band during a first period of time and transmitting user data into the first frequency band is performed during a second period of time which is different from the first period of time, said frequency band being used in a time division multiplexed manner. Timing information 2564, in some embodiments, identifies first and second periods of time. In various embodiments, the base station does not transmit or receive user data into a second frequency band designated to be used for peer to peer communications.

I/O interface 2508 couples the base station 2500 to other network nodes, e.g., other base station, AAA node, home agent nodes, etc. and/or the Internet. I/O interface 2508, by coupling base station 2500 to a backhaul network allows a wireless terminal using base station 2500 as its point of network attachment to participate in a communications session with another wireless terminal using a different base station as its point of network attachment.

Beacon signal generation module 2518 generates a beacon signal, said beacon signal including at least one beacon signal burst, said beacon signal burst conveying information about a peer to peer frequency band, e.g., identifying the peer to peer frequency band. Stored peer to peer beacon signal characteristic information 2528 is used by beacon signal generation module 2518 in generating the beacon signal. In some embodiments, the generated beacon signal by module 2518 conveys peer to peer communications band information 2560.

Frequency band control module 2520 controls transmission of the beacon signal generated by module 2518 into a first communications band, the beacon signal conveying information indicating a second frequency band which is used as the peer to peer frequency band, said second frequency band being different from the first frequency band. In some such embodiments, the first frequency band is the frequency band identified by peer to peer beacon signal transmission band information 2556 and the second frequency band is the frequency band identified by peer to peer communication band information 2560.

User data transmission control module 2522 controls transmission of user data to multiple ones of the plurality of wireless terminals using the base station as an access point using a transmission band identified by the base station access node information. In some embodiments, the band used for transmission of user data to a wireless terminal using the base station as a point of network attachment is the same as the first band which is the band into which the generated beacon signal for peer to peer communications is transmitted.

Transmission power control module 2524 controls transmission power into the second frequency band, which is the frequency band used for peer to peer communications, to keep the base station average transmitted power into the second frequency band over a 1 minute time period less than 1/1000 the average transmitted power transmitted into the first frequency band, e.g., the frequency band used for the beacon signal and access node related downlink signaling including user data. In some embodiments, the base station 2500 does not transmit into the second frequency band, which is used for peer to peer communications.

Access node beacon signal generation module 2526 uses the data/information 2516 including the access node beacon signal characteristic information 2534 to generate a second beacon signal, the second beacon signal providing timing synchronization information to the plurality of wireless terminals using the base station 2500 as an access node.

In some embodiments, (i) the band into which the beacon signal identifying the peer to peer band is transmitted, (ii) the band into which the beacon signal used for wireless terminal timing synchronization with regard to access node operations is transmitted, and (iii) the band used for downlink access node signaling to wireless terminals is the same band. In some such embodiments, the band used for peer to peer communications is a different, non-overlapping band. Thus information 2556, 2558, and 2562, in some embodiments, identify the same band, while information 2560 identifies a different band.

FIG. 18 is a drawing of an exemplary beacon signal transmission apparatus 1500 in accordance with various embodiments. Exemplary beacon signal transmission apparatus 1500 is a free standing device and does not include any transmitter used to transmit user data to an individual user device. Exemplary beacon signal transmission apparatus 1500 includes a receiver module 1502, a beacon signal transmitter 1504, a processor 1506, a solar power supply module 1508, a power supply module 1510, a memory 1512 coupled together via a bus 1514 over which the various elements may interchange data and information. The various elements (1502, 1504, 1506, 1408, 1510, 1512) are coupled to a power supply by bus 1507. Memory 1512 includes routines 1516 and data/information 1518. The processor 1506, e.g., a CPU, executes the routines 1516 and uses the date/information 1518 in memory 1512 to control the apparatus 1500 and implement methods.

Routines 1516 include a beacon signal transmission control module 1520, a beacon signal generation module 1522, a receiver control module 1524 and a received broadcast signal information recovery module 1526. Data/information 1518 includes stored beacon signal characteristic information 1528, stored beacon, signal control information 1530, received broadcast signal information 1532, and beacon transmitter identification information 1534. Stored beacon signal characteristic information 1528 includes one or more sets of beacon burst information (beacon burst 1 information 1536, . . . , beacon burst N information 1538), beacon symbol information 1540, and power information 1542. Beacon burst 1 information 1536 includes information identifying beacon transmission units carrying a beacon symbol 1544 and beacon burst duration information 1546. Stored beacon signal control information 1530 includes beacon burst/frequency band/timing relationship information 1548 and beacon burst/sector/timing relationship information 1550. Received broadcast signal information 1532 includes timing information 1552.

Receiver module 1502 is coupled to receive antenna 1501 via which the apparatus 1500 receives signals, e.g., a signal used for timing synchronization purposes. In some embodiments, the receiver is one of a GPS, GSM and CDMA receiver. In some embodiments, the receiver is an OFDM receiver. In some embodiments, the receiver module 1502 includes the capability to receive a plurality of different types of signals, and, e.g., depending upon the area of deployment a different type of signal is received and utilized as a reference source. In some such embodiments, the receiver control module 1524 follows a predetermined ordered sequence when determining reference signal search protocol.

Receiver 1502, under the control of receiver control module 1524, receives a broadcast signal and received broadcast signal information recovery module 1526 recovers received broadcast signal information 1532 from the received broadcast signal including timing information 1552, e.g., a timing reference.

Beacon signal transmitter 1504, e.g., an OFDM transmitter, is coupled to transmit antennas (sector 1 antenna 1503, . . . , sector N antenna 1505) via which the apparatus 1500 transmits beacon signal bursts which are used to support a peer-peer communications network. Beacon signal transmitter 1504 transmits a sequence of beacon signal bursts, each beacon signal burst including at least one beacon symbol. Beacon signal transmission control module 1520 uses the data/information 1518 in memory 1512 including stored beacon signal control data/information 1530 and timing information 1552 to control the transmission of beacon burnt signals, e.g., controlling beacon signal burst transmission timing as a function of the received broadcast signal which was detected and processed. Beacon signal transmission control module 1520 uses the data/information 1518 including timing information 1552 and beacon burst/frequency band/timing relationship information 1548 to control the beacon transmitter 1504 to transmit beacon signal bursts into different frequency bands at different times. Beacon signal transmission control module 1520 uses the data/information 1518 including timing information 1552 and beacon burst/sector/timing relationship information 1548 to control the beacon transmitter 1504 to transmit beacon signal bursts into sectors at different times. In some such embodiments, the beacon signal transmission control module 1520 controls the beacon signal transmitter 1504 to transmit into at most one sector at a time.

Solar power supply module 1508 includes solar cell 1509 for converting solar energy to electrical energy such that apparatus 1500 can be, and sometimes is solar powered. Power supply module 1510 includes battery 1511 for storing energy such that apparatus can be, and sometimes is powered by battery 1511. Some embodiments include a battery power supply 1511, but do not include a solar power supply module 1508, e.g., with the batteries being replaced and/or recharged periodically. In some embodiments, apparatus 1500 is expected to operate for the duration of the battery life and then be discarded or refitted with a replacement battery. In some embodiments, the beacons signal transmission apparatus 1500 is independently powered, e.g., operating from a portable gasoline, diesel, kerosene, propane, natural gas, and/or hydrogen based, generator and/or fuel cell. Embodiments using solar, battery and/or other independent energy sources are advantageous in remote sites, where a local power grid may be unavailable and/or in areas where a power grid is unreliable. In various embodiments, beacon signal transmission power is coupled to a power grid for receiving power.

Beacon signal generation module 1522 uses the data/information including stored beacons signal characteristic information 1528 and/or beacon transmitter identification information 1534 to generate a sequence of beacon signal bursts, each beacon signal bust including at least one beacon symbol, the beacon signal burst intended to be used to support peer to peer communications. Information identifying beacon transmission units carrying a beacon symbol 1544 include, e.g., information identifying a subset of OFDM tone-symbols designated to carry a high power beacon symbol in a set of OFDM tone-symbols of beacon burst 1. Beacon burst symbol information 1540 includes information defining a beacon symbol, e.g., a modulation symbol value, while power information 1542 includes transmission power level information associated with the beacon signal. In some embodiments, each of the beacon symbols is controlled to be transmitted at the same transmission power level. In some embodiments, each of the beacon symbols corresponding to a given sector and a given frequency band are controlled to be transmitted at the same transmission power level, with at least some beacon symbols corresponding to different sectors and/or frequency bands are transmitted at different power levels.

FIG. 19 is a drawing of a flowchart 2600 of an exemplary method of operating a beacon signal transmitter device in accordance with various embodiments. The beacon signal transmitter device is, e.g., a free standing device, and the beacon signal transmitter device does not include any transmitter used to transmit user data to an individual user device, e.g., wireless terminal. In various embodiments, the beacon signal transmitter device includes an OFDM beacon signal transmitter for transmitting OFDM beacon signal bursts, each beacon signal burst including at least one relatively high power OFDM beacon symbol, e.g., with respect to the transmission power levels of data symbols transmitted by wireless terminals communicating in a peer to peer communications session in the local region being serviced by the beacon signal transmitter device.

Operation starts in step 2602, where the beacon signal transmitter device is powered on and initialized. Operation proceeds from start step 2602 and proceeds to step 2604. In step 2604, the beacon signal transmitter device scans for different types of broadcast signals that can be used as timing reference signals. In some embodiments, the scanning is performed based on a predetermined sequence based on at least some geographic location information. Then, in step 2606, the beacon signal transmitter device receives a broadcast signal, and in step 2608 determines a signal burst transmission timing as a function of the received broadcast signal. In some embodiments, the receiver is a receiver which includes at least one of a GPS receiver, a GSM receiver, and a CDMA receiver. Operation proceeds from step 2608 to step 2610.

In step 2610, the beacon signal transmitter device is operated to transmit a sequence of beacon signal bursts, each beacon signal burst including at least one beacon symbol. Step 2610 includes sub-steps 2612, 2614, 2616, 2618, 2620, and 2622. In sub-step 2612, the beacon signal transmitter device's transmitter is powered from one of: a battery power source, a solar power source, and a power source which is independent of a commercial power grid.

In sub-step 2614, the beacon signal transmitter device compares current timing information to predetermined schedule information. Operation proceeds from sub-step 2614 to sub-step 2616, in which the beacon signal transmitter device determines if it is time to transmit a beacon signal burst or bursts. If it is determined in sub-step 2616, that it is not time to transmit a beacon signal burst, then operation proceeds back to step 2614 for additional comparison of timing information. However, if it is determined in sub-step 2616, that the beacon signal transmitter device is scheduled to transmit a beacon signal burst(s), then operation proceeds to sub-step 2618, where the device determines the frequency band or bands into which the beacon signal burst(s) are to be transmitted. Operation proceeds from sub-step 2618 to sub-step 2620, in which the device determines the sector or sectors into which the beacon signal burst or bursts are to be transmitted, Then, in sub-step 2622, the beacon signal transmitter device transmits the scheduled beacon signal burst or bursts into the determined frequency band or bands into the determined sector or sectors. Operation proceeds from sub-step 2622 back to sub-step 2614 for additional time comparisons.

In various embodiments, the beacon signal transmitter device uses stored control information to determine a plurality of frequency bands into which the beacon signal bursts are to be transmitted and the time at which the transmission of the beacon signal bursts are to occur. In some embodiments, the beacon signal transmitter device controls its transmitter to transmit beacon signal burst into different frequency bands at different times. In some embodiments, the beacon signal transmitter device controls its transmitter to use a multi-sector antenna and to transmit beacon signal bursts into different sectors at different times. In one such embodiment, the beacon signal transmitter device controls its transmitter to transmit into at most one sector at a time. In some embodiments, the beacon signal transmitter device controls its transmitter to transmit into at most one frequency band at a time.

In various embodiments, the beacon signal transmitter controls its transmitter to transmit into multiple frequency bands in each of multiple sectors of a cell. In some embodiments, the beacon signal transmitter is controlled to transmit into at most one frequency band of one sector at a given time at which beacon signal bursts are transmitted.

In some embodiments, described with respect to flowchart 2600, the beacon signal transmitter device obtains an external reference from a received broadcast signal. In some embodiments, the beacon signal transmitter does not include a receiver and does not receive a reference signal. For example, the beacon signal transmitter device transmits its beacon signal bursts in accordance with stored schedule information corresponding to a recurring schedule, and the beacon signal transmitter device's timing is free running and not coordinated with any other beacon signal transmitter device.

FIG. 20 is a drawing of a flowchart 1600 of an exemplary method of operating a base station in accordance with various embodiments. The exemplary base station switches between infrastructure spectrum use and peer to spectrum use. Thus at different times spectrum, e.g., a frequency band, in the vicinity of the base station is used for different purposes. Operation starts in step 1602, where the base station is powered on and initialized and proceeds to step 1604 and connecting nodes A 1606, B 1608, C 1610 and D 1612.

In step 1604, the base station sets its mode to a second mode, e.g., an access mode operation mode with respect to a first frequency band. In this particular exemplary embodiment, the access mode with respect to the first frequency band is the start-up default mode. In other embodiments, the peer to peer mode of operation is the start-up default mode, and the base station stats up in a mode in which the first frequency band is designated to be used for peer to peer communications. Operation proceeds from step 1604 to steps 1614 and step 1616.

In step 1614, the base station transmits a second broadcast signal during a second period of time conveying information that a first frequency band is be used as a non-peer to peer frequency band during a second period of time. In step 1616, during the second period of time, the base station operates as a network access point to relay information received over an airlink from a first communications device via a communications network to a second communications device. Operation proceeds from step 1614 and step 1616 to step 1618.

Returning to connecting node A 1606, operation proceeds via contacting node A 1606 to step 1628, where the base station monitors communications activity level during the second mode of operation. Operation proceeds from step 1628 to step 1630, in which the base station checks whether the activity is below a predetermined threshold. If the level of activity is below a predetermined threshold, then operation proceeds to step 1632, where the activity level information 1636 is updated to indicate a low level of activity, e.g., corresponding to a level in which the mode is to be switched in response to the determined low level. If the activity level is not below the threshold, then operation proceeds from step 1630 to step 1634 in which the base station updates the activity level information 1636 to indicate that the threshold is above the mode switch threshold, e.g., the base station should remain in the second mode based on the current level of activity. In some embodiments, the predetermined threshold corresponds to one wireless terminal currently using the base station as a network attachment point. In some embodiments, the predetermined threshold corresponds to one wireless terminal currently using the base station as a network attachment point and communicating at least some user data via the base station from and/or to that wireless terminal. Operation proceeds from step 1632 or step 1634 to step 1628 for additional monitoring.

Returning to connecting node B 1608, operation proceeds via connecting node B 1608 to step 1638, where the base station monitors for signals from wireless terminals, while in a first mode of operation, indicating that a wireless terminal is seeking to use the base station as an access point. Then, in step 1640, the base station checks if a signal was detected in step 1638. If a signal was detected operation proceeds from step 1640 to step 1642, where the base station updates the desired activity level information 1644. Operation proceeds from step 1642 to step 1638 for additional monitoring. If a signal was not detected in step 1640, operation proceeds from step 1640 to step 1638 for additional monitoring.

Returning to connecting node C 1610, the operation proceeds via connecting node C 1610 to step 1646, where the base station monitors for a override condition to occur. Step 1646 includes sub-step 1648 and sub-step 1650. In sub-step 1648, the base station monitors for receipt of a control signal indicating preemption of the first frequency band, e.g., by a government organization. In sub-step 1650, the base station monitors for receipt of a control signal indicating of preemption of the first frequency band, e.g., by a high priority user. Operation proceeds from step 1646 to step 1652.

In step 1652, the base station determines if a condition used to override the second mode of operation has occurred. If a condition has occurred, then operation proceeds from step 1652 to step 1654, where the base station updates the mode override information 1656; otherwise operation proceeds from step 1652 to step 1646 for additional monitoring. Operation proceeds from step 1654 to step 1646 for additional monitoring.

Returning to connecting node D 1612, operation proceeds via connecting node D 1612 to step 1658, where the base station monitors for a node change signal from a wireless terminal indicating that the wireless terminal has the authority to alter the current mode of base station operation. In some embodiments, the information indicating that the wireless terminal has the authority to alter the current mode of base station operation is one of a wireless terminal identifier, priority level indicated and a wireless terminal user identifier. Operation proceeds from step 1658 to step 1660, in which the base station determines whether such a mode change signal has occurred. If an authorized mode change signal has been detected, operation proceeds from step 1660 to step 1662, where the base station updates the authorized mode change information 1664; otherwise operation proceeds from step 1660 to step 1658 for additional monitoring. Operation proceeds from step 1662 back to step 1658 for additional monitoring.

Returning to step 1618, in step 1618, the base station makes a mode change determination as a function of the activity level information 1636, authorized mode change information 1664, and/or mode override information 1656. If the determination in step 1618, is that the mode should change, then operation proceeds to step 1620, where the base station switches from a second mode of operation to a first mode of operation in which the base station ceases to operate as an access node; otherwise operation proceeds from step 1618 to the input of steps 1614 and 1616 and operation continues in the second mode.

From step 1620, operation proceeds to step 1622, where the base station transmits a first broadcast signal during a first period of time, the first broadcast signal conveying information indicating that the first frequency band is to be used as a peer to peer frequency band. Operation proceeds from step 1622 to step 1624, where the base station determines whether the mode should be changed. The base station uses the desired activity level information 1642 and/or authorized mode change information 1664 in deciding whether to implement a mode change. If the decision of step 1624 is that the mode should be changed, then operation proceeds to step 1626, where the base station switches from the first mode of operation to the second mode of operation in which the base station operates as an access node; otherwise operation proceeds from step 1624 to the input of step 1622, and the base station continues to operate in the first mode, e.g., a mode supporting use of the first frequency band as a peer to peer band. Operation proceeds from step 1626 to the inputs of steps 1614 and step 1616, where the base station operates in the second mode as an access node.

FIG. 21 is a drawing of an exemplary base station 2700 in accordance with various embodiments. Exemplary base station 2700 includes the capability to control reallocation of frequency spectrum between infrastructure use, e.g., with the communications being directed through the base station 2700 functioning as an access node, and peer to peer spectrum use in which direct communications links between peer wireless terminals are used.

Exemplary base station 2700 includes a receiver module 2702, a transmission module 2704, a processor 2706, an I/O interface 2708, and memory 2710 coupled together via a bus 2712 over which the various elements may interchange data and information. Memory 2710 includes routines 2714 and data/information 2716. The processor 2706, e.g., a CPU, executes the routines 2714 and uses the data/information 2716 in memory 2710 to control the operation of the base station and implement methods, e.g., the method of FIG. 20.

Receiver module 2702, e.g., an OFDM receiver, is coupled to receive antenna 2701 via which the base station 2700 receives signals from wireless terminal, e.g., when the base station is functioning as an access node. Transmission module 2704, e.g., an OFDM transmitter, is coupled to transmit antenna 2703, via which the base station 2700 transmits signals to wireless terminals. The transmitted signals include broadcast signals such as beacon signals used to identify whether a frequency spectrum is to be used in an access mode of operation or in a peer to peer communications session mode of operation. When the base station 2700 is using spectrum in an access mode of operation, the transmitter 2704 also transmits downlink signals, e.g., pilot channel signals, control channel signals and user data signals, e.g., traffic channel signals to wireless terminals using the base station 2700 as a point of network attachment.

Transmission module 2704 transmits a 1^(st) broadcast signal during a 1^(st) period of time, the first broadcast signal conveying information indicating that a first frequency band is to be used as a peer to peer frequency band, and transmits a second broadcast signal during a second period of time, the second broadcast signal conveying information indicating that the first frequency band is to be used as a non-peer to frequency band during the second period of time. In some embodiments, the 1^(st) and 2^(nd) broadcast signals are beacon signals e.g., OFDM beacon signals. 1^(st) broadcast signal is generated by base station 2700 based upon 1^(st) broadcast signal information 2730, e.g., information identifying beacon symbols in beacon signal bursts and timing beacon burst timing information representing the 1^(st) broadcast signal, conveys peer to peer frequency band information. 2^(nd) broadcast signal is generated by base station 2700 based upon 2^(nd) broadcast signal information 2732, e.g., information identifying beacon symbols in beacon signal bursts and timing beacon burst timing information representing the 2^(nd) broadcast signal, and conveys non-peer to peer frequency band information 2744. Thus a wireless terminal can monitor for the presence of 1^(st) and 2^(nd) broadcast signals from base station 2700 and depending upon which one is detected, determine how the first frequency band is currently being used.

I/O interface 2708 couples the base station 2700 to other network nodes, e.g., other base station AAA nodes, home agent nodes, etc. and/or the Internet. I/O interface 2708, by coupling base station 2700 to a backhaul network allows a wireless terminal using base station 2700 as its point of network attachment to participate in a communications session with another wireless terminal using a different base station as its point of network attachment.

Routines 2714 include a transmitter control module 2718, a routing module 2720, a mode control module 2722, a monitoring module 2724, a security module 2726, and an activity level monitoring module 2728. The mode control module 2722 includes an override module 2723. Data/information 2716 includes 1^(st) broadcast signal information 2730, 2^(nd) broadcast signal information 2732, transmission timing information 2734, mode of operation information 2736, detected access request signal information 2738, security information 2740, peer to peer frequency band information 2742, non-peer to peer frequency band information 2744, network topology information 2746, current network routing information 2748, determined current level of communications activity information 2750 and activity level based switching criteria 2756. The determined current level of communications activity information 2750 includes a determined bandwidth utilization level 2752 and a determined number of active wireless terminal users 2754. Activity level based switching criteria 2756 includes a bandwidth utilization switching threshold 2758 and a number of active terminals switching threshold 2760.

Transmitter control module 2718 controls the transmission module 2704 to transmit said first and second broadcast signals during said first and second periods of time, respectively, said first and second periods of time being non-overlapping. Routing module 2720, which is used during the second period of time, routes user data received over an airlink from a first communications device to a second communications device via a communications network coupled to said base station. Routing module 2720 uses network topology information 2746 and current network routing information 2748, e.g., information identifying congestion locations, failed nodes, alternative routing costs, delay consideration information, etc., to determined user data routing.

Mode control module switches between first and second modes of operation. The current mode of operation into which the base station has been switched is indicated by mode of operation information 2736. The first mode of operation corresponds to a mode during the first periods of time in which the first frequency band is being utilized as a peer to peer frequency band, while the second mode of operation is a mode of operation in which the first frequency band is being utilized for non peer to peer communications with the base station 2700 serving as an access node. When the mode control module 2722 switches from the second mode of operation to the first mode of operation the mode control module 2722 stops the base station 2700 from acting as an access node, e.g., with regard to the first frequency band in the region into which the 1^(st) broadcast signal transmission is directed.

Monitoring module 2724 monitors for and detects signals from wireless terminals that are seeking to use the base station 2700 as an access node. For example, the base station 2700 may be currently in the first mode of operation in which the first band is being used for peer to peer communications; however, a wireless terminal may desire that the base station reallocate the spectrum to access node operation, and send an access request signal to the base station which is detected and recovered by monitoring module 2724. The recovered information is, e.g., detected access request signal information. In some embodiments, the detected access request signal information includes information indicating that the wireless terminal making the request has the authority to command the requested change. For example, the information indicating that the wireless terminal has the authority to alter the current mode of base station operation is, in some embodiments communicated by one of a wireless terminal identifier, a priority level indicated, and a wireless terminal user identifier. Security information 2740 includes information utilized in making authorization evaluations e.g., lists of authorized users, wireless terminal, and/or priority level interpretation information. The base station 2700 considers the request in making a decision as to whether or not to switch modes. For example, the base station switches from the first mode of operation to the second mode of operation in response to a signal received from a wireless terminal indicating that the wireless terminal is seeking to use the base station as an access node.

Security module 2726, using security information 2740, determines that a signal requesting a mode change is from a wireless terminal or user having the authority to command the requested mode change.

Activity level monitoring module 2728 determines the level of communications activity 2750 while the base station is in the second mode of operation functioning as an access node. The mode control module 2722 is responsive to a low activity level, which it uses to initiate a switch from the second mode of operation to the first mode of operation. In some embodiments, at some times, a low level of activity is indicated by determined bandwidth utilization level 2752 being below a predetermined threshold, the bandwidth utilization switching threshold 2758. In some embodiments, at some times, a low level of activity is indicated by determined number of active wireless terminals 2754 being below a predetermined threshold, the number of active terminals switching threshold 2760. In various embodiments, the determined number of active wireless terminals 2754 indicates the number of wireless terminals currently using the base station as an access point. In some embodiments, the number of active terminals switching threshold is set to 1.

Override module 2723 detects when a current mode override condition occurs. The current mode override condition is, e.g., the receipt of a control signal indicating preemption of the first frequency band. The preemption can be, and sometimes is, by a government organization. Alternatively, the preemption can be, and sometimes is, by a high priority user. The control signal can be communicated over an airlink and received via receive module 2702 or communicated over the backhaul network and received via I/O interface 2708.

FIG. 22 is a drawing of a flowchart 1700 of an exemplary method of operating a wireless device, e.g., a mobile node, in accordance with various embodiments. Operation starts in step 1702, where the wireless device is powered on and initialized and proceeds to step 1704, where the wireless device establishes a communications link with a base station. Then in step 1706, the wireless device monitors for broadcast signals from the base station while maintaining the link. Operation proceeds from step 1706 to step 1708.

In step 1708, the wireless device checks whether a predetermined change in at least one of said broadcast signal indicative of a change in communications mode of operation from a cellular mode to a peer to peer mode has been detected. In some embodiments, the change in at least one of said broadcast signals is a change in a beacon signal, e.g., a change in an OFDM beacon signal being transmitted by the base station. In some such embodiments, the change includes a change in information communicated by the beacon signal. In various embodiments, the information communicated by the beacon signal indicates a peer to peer mode of frequency spectrum use after said change. If in step 1708 the wireless device detected a change in a broadcast signal indicative of a change in communications mode of operation from a cellular in ode to a peer to peer mode, then operation proceeds from in step 1708 to step 1710; otherwise operation proceeds from step 1708 to step 1706 for additional monitoring.

In step 1710, the wireless device, in response to detecting the change, ceases to maintain the link. Step 1710 includes sub-step 1710 in which the wireless device terminates control signaling used to maintain said link. Operation proceeds from step 1710 to step 1714, in which wireless device starts to maintain transmission silence. Then, in step 1716, the wireless device ceases communication with the base station in the frequently spectrum previously used by the communications link. Operation proceeds from step 1716 to step 1720. In step 1720, the wireless device switches from a cellular mode of operation to a peer to peer mode of operation. Operation proceeds from step 1720 to step 1722.

In step 1722, the wireless device checks for a peer to peer session initiation event. For example, a session initiation event is, e.g., a signal from a peer requesting session establishment, or a decision by the wireless device to attempt to establish a peer session with another wireless terminal detected or known to be in the region. In response to a session initiation event, operation proceeds form step 1722 to step 1726, where the wireless device establishes a peer to peer communications session with another wireless terminal. If a peer to peer session initiation event was not detected, then operation proceeds from step 1722 to step 1724, where the wireless device continues to maintain transmission silence. In some other embodiments, while in the peer to peer mode, the wireless device transmits some broadcast signals, e.g., some user beacon signals, irrespective of whether or not the wireless terminal is in a communications session.

Operation proceeds form step 1724 or step 1726 to step 1728, where the wireless device continues to monitor for signals from the base station, e.g., broadcast signals such as beacon signals conveying spectrum usage information. Operation proceeds from step 1728 to step 1730. In step 1730, the wireless device determines whether a broadcast signal indicating a cellular mode of operation was detected. If such a signal was detected, operation proceeds from step 1730 to step 1732; otherwise, operation proceeds from step 1730 to step 1728 for additional monitoring.

In step 1732, the wireless device terminates the peer to peer communications session with said another terminal, if such a session was established. Then, in step 1734, the wireless device re-establishes a link with the base station, e.g., with the wireless device having remained in the coverage area corresponding to the base station between the time the link ceased to be maintained and the time the link was re-established.

FIG. 23 is a drawing of an exemplary wireless terminal 2800, e.g., mobile node in accordance with various embodiments. Exemplary wireless terminal 2800 can, and sometimes does, switch between a cellular operation mode and a peer to peer operational mode in response to received broadcast signals, e.g., beacon signals. Wireless terminal 2880 includes a receiver module 2802, a transmitter module 2804, a processor 2806, user I/O devices 2808, and memory 2810 coupled together via a bus 2412 over which the various elements may interchange data and information. Memory 2810 includes routines 2814 and data/information 2816. The processor 2806, e.g., a CPU, executes the routines 2814 and uses the data/information 2816 in memory 2810 to control the operation of the wireless terminal 2800 and implement methods, e.g., a method in accordance with FIG. 22.

Routines 2814 include a communications routine 2818 and wireless terminal control routines 2820. The communications routine 2818 implements the various communications protocols used by the wireless terminal 2800. Wireless terminal control routines 2820 include a link establishment module 2822, a broadcast signal monitoring module 2824, a mode determination module 2826, a mode control module 2828, a control signaling module 2830, a link re-establishment module 2832, and a peer to peer communications establishment module 2834. Mode control module 2828 includes switching module 2829.

Data/information 2816 includes detected broadcast signal information 2836, detected change in broadcast signal information 2840, determined mode of operation communicated by broadcast signaling 2842, spectrum usage information 2848, wireless terminal current mode of operation information 2844, and generated control signals 2846. Data/information 2816 also includes broadcast signals' identification information 2850 and broadcast signals'0 information recovery information 2852. The broadcast signals' identification information 2850 includes beacon symbol energy level detection information 2854, and beacon symbol pattern information 2856. Broadcast signals' information recovery information 2852 includes beacon signal to mode mapping information 2858 and beacon signal to spectrum usage mapping information 2860.

Receiver module 2802, e.g., an OFDM receiver, is coupled to receive antenna 2803 via which the wireless terminal receives signals. Receiver module 2802 receives broadcast signals from base stations. The broadcast signals include, e.g., beacon signaling used to communicate a current mode of spectrum usage. When the base station is functioning as an access node, the wireless terminal receiver 2802 can, and sometimes does, receive control signals and user data signals from the base station in the spectrum. When the spectrum is being utilized for peer to peer communications, the wireless terminal receiver 2802 can, and sometimes does, receive signals directly from a peer wireless terminal, e.g., user beacon signals, peer to peer session establishment signals, and user data signals as part of a peer to peer communication session.

Transmitter module 2804, e.g., an OFDM transmitter, is coupled to transmit antenna 2805 via which the wireless terminal 2800 transmits signals. In some embodiments, the same antenna is used by the transmitter and receiver. Transmitted signals include, e.g., access node based session establishment signals, peer to peer node session establishment signals, control signal to an access node as part of maintaining a link with the access node, user data signals to an access node, and user data signals to a peer node as part of a peer to peer communication session.

User I/O devices 2808 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 2808 are used for operations including inputting user data, accessing output user data, and controlling at least some functions and operations of the wireless terminal, e.g., initiating a communications session.

Link establishment module 2822 establishes a communications link with a base station. Broadcast signal monitoring module 2824 monitors to detect broadcast signals from base stations. Mode determination module 2826 determines a communications mode of operation from at least one broadcast signal from a base station detected by the monitoring of module 2824. In various embodiments, the broadcast signal from the base station used by the mode determination module 2826 for its determination is a beacon signal. In some embodiments, the mode determination is based on a change in a beacon signal, e.g., as indicated in detected change in broadcast signal information 2840. In some such embodiments, the change indicates a change in information communicated by the beacon signal. For example, the information communicated by the beacon signal indicates a peer to peer frequency spectrum use after the change, while the beacon signal information before the change indicates a cellular mode usage of the spectrum. As another example, the information communicated by the beacon signal indicates a cellular mode spectrum use after the change, while the beacon signal information before the change indicates a peer to peer mode usage of the spectrum.

Mode control module 2828 controls the wireless terminal 2800 to operate in the mode determined by the mode determination module 2826. The mode control module 2828 can, and sometimes does, drop an established link with a base station when the mode determination module 2826 indicates a change in a communication mode of operation from a cellular mode to a peer to peer mode of operation. Switching module 2829 switches the wireless terminal 2800 from a cellular mode of operation to a peer to peer mode of operation in response to detecting a predetermined change in at least one of the broadcast signals. Wireless terminal current mode of operation 2844 indicates the current mode of wireless terminal operation, e.g., cellular mode or peer to peer mode, into which the wireless terminal has been switched.

Control signaling module 2830 generates control signals 2846 to maintain an established link with a base station. Generated control signals 2846 include, e.g., power control signals, timing control signals, control channel report signals such as SNR reports, etc. When the mode control module 2828 drops an established link with a base station, the mode control module 2828 controls the control signaling module 2830 to stop generating control signals used to maintain the link.

Link re-establishment module 2832 re-establishes a link with a base station in response to detecting a broadcast signal indicating a cellular mode of operation. Peer to peer communications establishment module 2834 is used to establish a peer to peer communications session with another wireless terminal, e.g., during at least a portion of the time between which said link is ceased to be maintained with the base station and the link is re-established with the base station.

Detected broadcast signal information 2836, e.g., detected beacon signal information is an output of broadcast signal monitoring module 2824. Broadcast signal monitoring module 2824 uses the data/information 2816 including the broadcast signals' identification information 2850 to detect beacon signals. Beacon symbol energy level detection information 2854 includes energy level criteria used for identifying beacon symbols from among a plurality of received signals. For example, a beacon signal includes a beacon signal burst including at least a beacon symbol and the beacon symbol is transmitted at a relatively high energy level with respect to other signals transmitted by the base station, facilitating easy detection by a wireless terminal. Beacon symbol pattern information 2856 includes information identifying sets of beacon symbols within a set of beacon symbol transmission units. For example, a particular pattern of beacon symbols may, and sometimes does represent a particular beacon signal.

Mode determination module 2826 uses the data/information 2816 including the broadcast signals' information recovery information 2852 to determine a mode of operation being communicated by the broadcast signal 2842, e.g., one of a cellular mode and a peer to peer mode, and spectrum usage information 2848, e.g., one of a cellular mode spectrum allocation and a peer to peer mode spectrum allocation. In some embodiments the cellular mode spectrum usage information further identifies one of a time division duplex use of spectrum and a frequency division duplex use of spectrum. For example, the base station when functioning as an access node may operate in a TDD manner in which the spectrum is alternately used for downlink and uplink, or the base station may operate using two distinct bands for uplink an downlink which allow simultaneous uplink and downlink signaling.

FIG. 24 is a drawing of a flowchart 1800 of an exemplary method of operating a mobile communications device in a system including a base station in accordance with various embodiments. Operation starts in step 1802, where the mobile communications device is powered on and initialized and proceeds to step 1804. In step 1804, the mobile communications device determines a base station mode of operation, the base station mode of operation being one of an access mode of operation in which the base station operates as a network access node and a peer to peer mode of operation in which devices within a base station coverage area are allowed to communicate directly with one another. Operation proceeds from step 1804 to step 1806.

In step 1806, the mobile communications device, sends a signal to a base station to signal a wireless terminal desired change in the mode of base station operation. Then, in step 1808, the mobile communications device monitors for a broadcast signal from the base station indicating a change in base station mode of operation to the indicated mode desired by the mobile communications device. Operation proceeds from step 1808 to step 1810. In step 1810, the mobile communications device checks if the monitored for signal has been detected. If the monitored for signal was detected, then operation proceeds from step 1810 to step 1812; otherwise, operation proceeds from step 1810 to step 1808 for additional monitoring. In some embodiments, a timeout is associated with the duration of the monitoring, and if the mobile communications device does not receive the monitored for signal within the allocated time, the mobile communications device needs to resend the desired change signal.

In step 1812, the mobile communications device changes the mode of the mobile communications device operation to the mode to which the base station has changed. Operation proceeds from step 1812 to step 1814. In step 1814, the mobile communications device signals the base station to switch from the indicated mode of operation to the base station's previous mode of operation.

In some embodiments, the signal of step 1804 indicates a desire for a change from a network access mode of operation to a peer to peer mode of operation. In some embodiments, the signal of step 1804 includes information indicating a level of authority said mobile communications device has to control the base station operation. In some such embodiments, the information indicating the level of authority is one of a device identifier, user identifier, and priority level indicator.

In various embodiments, the mobile communications device is a device used by a government agent with authority to override use of the spectrum used by the base station.

In some embodiments, the mobile communications device is a cellular network device, and the desired change of step 1806 is a change from a peer to peer mode to a network mode of operation. In some such embodiments, the cellular network device does not support peer to peer operation.

In various embodiments, the mobile communications device is a peer to peer device and the desired change is a change from a network access mode to a peer to peer mode of operation. In some such embodiments, the peer to peer device does not support a cellular network mode of operation. In some embodiments, the peer to peer device which does not support a cellular network mode of operation is a device used by a government agent with authority to override the use of the spectrum by the base station.

FIG. 25 is a drawing of an exemplary wireless terminal 2900, e.g., mobile node, in accordance with various embodiments. Exemplary wireless terminal 2900 includes the capability to influence a base station's mode of operation, e.g., requesting and/or commanding switching between a cellular mode and a peer to peer mode.

Exemplary wireless terminal 2900 includes a receiver module 2902, a transmitter module 2904, a processor 2906, user I/O devices 2908, and memory 2910 coupled together via a bus 2912 over which the various elements may exchange data and information. Memory 2910 includes routines 2914 and data/information 2916. The processor 2906, e.g., a CPU, executes the routines 2914 and uses the data/information 2916 in memory 2910 to control the operation of the wireless terminal and implement methods, e.g., a method in accordance with FIG. 24.

Routines 2914 include communications routine 2918 and wireless terminal control routines 2920. The wireless terminal control routines 2920 include a base station mode of operation determination module 2922, a signal generation module 2924, a broadcast signal detection module 2928 and a communications mode control module 2930. The signal generation module 2924 includes a base station mode restoration module 2926.

Data/information 2916 includes a determined base station mode of operation 2932, a generated change signal 2934, and stored information indicating the level of authority the wireless terminal has to control the base station operations 2936. Information 2936 includes a wireless terminal device identifier 2938, a wireless terminal user identifier 2940, and a priority level indicator 2942. Data/information 2916 also includes detected broadcast signal information 2944 and current mode of wireless terminal operation information 2946.

The receiver module 2902, e.g., an OFDM receiver, is coupled to receive antenna 2903, via which the wireless terminal 2900 receives signals. Received signals include received broadcast signals, e.g., beacon signals, from a base station from which a base station mode of operation can be determined.

Transmitter module 2904, e.g., an OFDM transmitter, is coupled to transmit antenna 2905, via which the wireless terminal 2900 transmits signals. Transmitted signals include generated change signal 2934 conveying a wireless terminal 2900 desire for a base station to change its mode of operation. Transmitter module 2904 sends the generated change signal 2934 to the base station to communicate the wireless terminal's desired change in the base station's mode of operation. The generated change signal 2934 can be, and sometimes is, a request for the base station to change modes. The generated signal 2934 can be, and sometimes is, a command to the base station to change its mode of operation.

User I/O devices 2908 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 2908 are used for operations including inputting user data, accessing output user data and controlling at least some functions and operations of the wireless terminal, e.g., initiating a communications session. In some embodiments, the user I/O devices 2908 include a special purpose key, switch or button, for use to command a mode switch of the base station. For example, the wireless communications device 2900 is used by a government agent with authority to override use of the spectrum by the base station and includes a special purpose button on the wireless terminal, which when depressed, initiates the generation and transmission of a mode change control signal directed to the base station.

Communications routine 2918 implements the various communications protocols used by the wireless terminal 2900. Base station mode of operation determination module 2922 determines a base station's mode of operation, the base station mode of operation being one of an access node mode of operation in which the base station operates as a network access node and a peer to peer mode of operation in which devices within a base station coverage area are allowed to communicate directly with one another. Determined base station mode of operation 2932 is an output of determination module 2922.

Signal generation module 2924 generates a signal change signal 2934 indicating a wireless terminal desired change in the base station's mode of operation. At times, the generated change signal 2934 indicates a desire for a change from a network access mode of operation to a peer to peer mode of operation. At times, the generated change signal 2934 indicates a desire for a change from a peer to peer mode of operation to network access mode of operation.

In some embodiments, the change signal conveys a level of authority associated with the change signal. The level of authority, in some embodiments, is based on one or more of wireless terminal identifier, user identifier, and a priority level indicator. In some embodiments, wireless terminal 2900 has a fixed level of authority associated with the device. In some embodiments, wireless terminal 2900 has a variable level of authority, e.g., which changes a function of user identification information and/or priority level access code information. In some such embodiments, the user I/O devices 2908 include a biometric input device for receiving biometric information corresponding to the user, the input biometric information being used to obtain/authenticate authorization information.

Base station mode restoration module 2926 generates a restoration signal 2935 to be communicated to a base station, the restoration signal to signal the base station to switch from the indicated mode of operation communicated by the previous change signal to the base station, the indicated mode being the mode in which the base station is currently operating, to the previous mode of base station operation.

Broadcast signal detection module 2928 detects a broadcast signal which indicates that the base station has changed the base station mode of operation to an indicated node of operation desired by the wireless terminal. Detected broadcast signal information 2944 is an output of detection module 2928. In various embodiments, the detected broadcast signals are beacon signals, e.g., OFDM beacon signal.

Communications mode control module 2930 changes the operational mode of the mobile communications device, as indicated by current mode of wireless terminal operation, to match the mode of base station operation to which the base station has transitioned as indicated by a detected broadcast signal. In various embodiments, the wireless terminal 2900 supports communications sessions in both cellular, e.g., access node based mode and peer to peer mode. In some embodiments, the wireless terminal does not support communications sessions in one of the cellular and peer to peer modes of operation. In some such embodiments, the wireless terminal enters a standby state while the spectrum is allocated for the mode in which the wireless terminal can not participate in a communication session, e.g., conserving power.

In some embodiments, the wireless terminal 2900 is a device used by a government agent with the authority to override use of the spectrum used by a base station. In some embodiments, the wireless terminal 2900 is a cellular network device, and the wireless terminal indicates a desired change from a peer to peer to a network access mode of operation. In some such embodiment, the cellular network device does not support peer to peer communications. In some embodiments, the wireless terminal 2900 is a peer to peer device, and the wireless terminal indicates a desired change from a network access mode of operation to a peer to peer mode of operation. In some such embodiments, the cellular network device does not support a cellular network mode of operation. In some embodiments, the wireless terminal is a mobile communications device used by a government agent with authority to override use of the spectrum by the base station.

In one embodiment, which is a variation based on wireless terminal 2900, the wireless terminal is a mobile communications device used by a government agent with the authority to override the use of spectrum by the base station, and the device communicates mode change command signals, but does not support either access node based or peer to peer based communications sessions.

FIG. 26 is a drawing of a flowchart 1900 of an exemplary method of operating a wireless device, e.g., a mobile node, in accordance with various embodiments. Operation starts in step 1902, where the wireless device is powered on and initialized. Operation proceeds from start step 1902 to step 1904, where the wireless device receives a first broadcast signal from a base station. Then, in step 1906, the wireless device determines from the received first broadcast signal that a frequency band corresponding to the base station is being used for peer to peer communications. Operation proceeds from step 1906 to step 1908.

In step 1908, the wireless device receives a second broadcast signal from the base station, and then in step 1910, the wireless device determines from the received second broadcast signal that the second frequency band has been changed to be used as a cellular network band. In response to determining that the frequency band is to be used as a cellular frequency band, operation proceeds from step 1910 to one of alternate steps 1912, 1914, and 1916. In alternative step 1912, the wireless device reduces transmission power. In some embodiments, reducing transmission power includes a reduction in transmission power by at least 10 dBs. In some embodiments, reducing transmission power includes ceasing to transmit. In alternative step 1914, the wireless device terminates an ongoing peer to peer communications session. In alternative step 1916, the wireless device puts an ongoing peer to peer communications session into a hold state. Operation proceeds from any of steps 1912, 1914, 1916 to step 1918. If the wireless terminal does not have an ongoing peer to peer communications session when making the determination of step 1910, operation proceeds from step 1910 to step 1918 without traversing alternative steps 1912, 1914, or 1916.

In step 1918, the wireless device receives a third broadcast signal from the base station, and then in step 1920, the wireless device determines from the third broadcast signal that said frequency band has been changed to be used for peer to peer communications. Operation proceeds from step 1920 to step 1922, where the wireless device switches a peer to peer communications session, which was in hold state, if one happens to exist in hold state, to an active state in response to said third broadcast signal.

In some embodiments at least some of the received first, second and third broadcast signals include beacon signal bursts. In some embodiments, each of the first, second, and third signals are OFDM beacon signals.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal 3000 supports peer to peer communications sessions. In some embodiments, exemplary wireless terminal 3000 supports peer to peer communications but does not support a cellular mode of operation. Exemplary wireless terminal 3000 includes a receiver module 3002, a transmission module 3004, a coupling module 3003, a processor 3006, user I/O devices 3008, a power supply module 3010 and memory 3012 coupled together via a bus 3014 over which the various elements may interchange data and information. Memory 3012 includes routines 3016 and data/information 3018, The processor 3006, e.g., a CPU, executes the routines and uses data/information 3018 in memory 3012 to control the operation of the wireless terminal 3000 and implement methods, e.g., a method in accordance with FIG. 26.

Coupling module 3003, e.g., a duplex module, couples the receiver module 3002 to antenna 3005 and the transmission module 3004 to antenna 3005, e.g., coordinating time division duplex operations of wireless terminal 3000. Power supply module 3012, which includes a battery 3011, is used to power up the various components of the wireless terminal 3000. Power is distributed from the power supply module 3010 to the various components (3002, 3003, 3004, 3006, 3008, 3012), via a power bus 3009. User I/O devices, 3008 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 3008 are used for operation including inputting user data, accessing output user data, and controlling at least some functions and operations of the wireless terminal, e.g., maintaining a peer to peer communications session.

Routines 3016 include a mode determination module 3020, a mode control module 3022, a peer to peer communications session termination module 3024, a session hold module 3026, and a peer to peer communications session reestablishment module 3028. Data/information 3018 includes received broadcast signals 3030, a determined mode of communications operation 3032, wireless terminal controlled mode information 3034, a current level of transmission power information 3035, power reduction information 3036, 1^(st) maximum transmission power level information 3038, 2^(nd) in maximum transmission power level information 3040, and peer to peer communications session information 3042. The peer to peer communications session information 3042 includes status information 3044, peer node information 3046, user data information 3048, and state information 3050.

Receiver module 3002, e.g., an OFDM receiver, receives signals including broadcast signals. Receiver module 3002 also receives, at times, user data signals from a peer wireless terminal in a peer to peer communications session with wireless terminal 3000. Received broadcast signals 3030, e.g., beacon signals, are used to determine a mode of communication band operation.

Transmitter module 3004, e.g., an OFDM transmitter, transmits user data as part of a peer to peer communications session. In some embodiments, transmission module 3004 also transmits user beacon signals, e.g., OFDM user beacon signals.

Mode determination module 3020 determines based on received broadcast signals 3030 a mode of communications band operation, determined mode of communications band operation 3032. The determined mode of communications band operation indicating a mode of operation in which the frequency band is to be used at a point in time, the determined mode of communication band operation being one of a plurality of frequency band modes including at least a cellular communications mode and a first peer to peer communications mode.

Mode control module 3022 controls wireless terminal 3000 device operation as a function of at least one of a mode determination and a change in a determined mode of communications band operation, said mode control module 3022 controlling the transmitter to reduce power in response to determining that the frequency band is to be used as a cellular frequency band. In some embodiments, the controlling the transmitter to reduce power includes reducing transmission power by at least 10 dBs. In some embodiments reducing transmission power includes ceasing to transmit.

Thus, in some embodiments, when wireless terminal 3000 is in a peer to peer communications session and the spectrum is reallocated to support access node based operations, the wireless terminal is permitted to continue the peer to peer communications session at a reduced power level. While, in other embodiments, when wireless terminal 3000 is in a peer to peer communications session and the spectrum is reallocated for access node based operation, the wireless terminal terminates or suspends the peer to peer communications session until the spectrum is reallocated for peer to peer usage. In some embodiments, wireless terminal 3000 decides whether to continue with, terminate, or place on hold a peer to peer session interrupted by a spectrum reallocation, in response to other factors, e.g., device identification information, user identity information, priority information, latency requirements, etc.

Peer to peer communications session termination module 3024 terminates at least some peer to peer communications sessions in response to a determination that a frequency band is being used as a cellular frequency band. Session hold module 3026 puts an ongoing peer to peer communications session into a hold state in response to a determination that the frequency band is being used as a cellular frequency band. Peer to peer communications session reestablishment module 3028 transitions a peer to peer communications session from a hold state to an active state in response to a determination that the frequency band is to be used for peer to peer communications.

Current level of transmission power information 3035 is a monitored level used by mode control module 3022, when determining a transmission power level reduction in accordance with power reduction information 3036, e.g., a gain factor of at least 10 dBs, and 1^(st) maximum transmission power level information 3038 and 2^(nd) maximum level transmission power information 3040. The power level reduction is in response to a detection that spectrum usage is changing from peer to peer to cellular based, and the wireless terminal 3000 continuing with the peer to peer communications session at a reduced power level. In some embodiments, the mode control module 3022 supports 1^(st) and 2^(nd) modes of peer to peer operation from the perspective of the wireless terminal, the second peer to peer mode of operation being a reduced power level mode of operation in which the wireless communications device 3000 uses a lower maximum transmission power level for the transmission of user data than is used in the 1^(st) mode of peer to peer operation. Ii some embodiments, the 1^(st) mode of wireless terminal peer to peer operation applies when the spectrum is allocated for peer to peer usage, and the second mode of wireless terminal peer to peer operation applies when the spectrum is allocated primarily for cellular access node base operations.

Status information 3044 indicates whether the peer to peer communications session is in an active state or a hold state. Status information 3044 also indicates whether the peer to peer communications session is in a first mode of wireless terminal peer to peer operation, e.g., normal power mode, or a second mode of wireless terminal peer to peer operation, reduced power mode. Peer node information 3046 includes peer node identification information, addressing information, and priority level information. User data information 3048, e.g., voice, image, text, file information, includes user data to be transmitted and received as part of the peer to peer communications session. State information 3050 includes session maintenance information, and stored information used to reestablish a session placed into a hold state.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawing of a flowchart 2000 of an exemplary communications method in accordance with various embodiments. Operation of the exemplary communications method starts in step 2002 and proceeds to step 2004, step 2024 via connecting node A 2006, and step 2030 via connecting node B 2008.

In step 2004, a first wireless terminal capable of supporting peer to peer operations and cellular network operations is operated. Step 2004 includes sub-steps 2010, 2011, 2012, 2014, 2016, 2018, and 2020. In sub-step 2010, the first wireless terminal monitors for paging signals from a base station during a first set of time intervals which are paging time intervals. In various embodiments, during the first set of time intervals the first wireless terminal does not transmit peer to peer signals. In some embodiments, during the first set of time intervals the first wireless terminal also does not receive peer to peer signals.

In sub-step 2012, the first wireless terminal, during a second set of time intervals, which do not overlap said first set of time intervals, is operated to participate in a peer to peer communications session. In some embodiments, the first and second time intervals are interleaved. Sub-step 2012 includes sub-step 2022, in which the first wireless terminal, during at least a portion of said second set of time intervals is operated to transmit a first wireless terminal identifier used for peer to peer communications. In some such embodiments, the first wireless terminal identifier is communicated via a user beacon signal, e.g., an OFDM user beacon signal including a beacon signal burst including at least one beacon symbol.

In some embodiments, the same frequency band is used for paging and for peer to peer communications, and the first wireless terminal need not perform sub-step 2011. In some embodiments, different frequency bands are used for paging and for peer to peer communications. In some such embodiments, sub-step 2011 is performed in which the first wireless terminal switches the frequency band of a receiver in said wireless terminal when switching between monitoring for pages during a first time interval and operating in a peer to peer mode during a second time interval.

Returning to sub-step 2010, for a detected page signal directed to the first wireless terminal, operation proceeds from sub-step 2010 to sub-step 2014. In sub-step 2014, the first wireless terminal decides whether to establish a link with the base station in response to the page directed to the first wireless terminal or to continue with an ongoing peer to peer communication session. In some embodiments, the decision of the step 2014 is a function of at least one of: a priority level associated with the ongoing peer to peer communications session, a priority level associated with the peer wireless terminal in the ongoing peer to peer communications session, a priority level associated with the user of the peer wireless terminal in the ongoing peer to peer communication session, the type of data being communicated in the peer to peer communications session, latency considerations of the data being communicated in the peer to peer session, an estimate of the amount of data remaining to be communicated in the peer to peer communications session, and priority information communicated in the page signal. In some such embodiments, the decision of step 2014 is a function of at least two of: a priority level associated with the ongoing peer to peer communications session, a priority level associated with the peer wireless terminal in the ongoing peer to peer communications session, a priority level associated with the user of the peer wireless terminal in the ongoing peer to peer communication session, the type of data being communicated in the peer to peer communications session, latency considerations of the data being communicated in the peer to peer session, an estimate of the amount of data remaining to be communicated in the peer to peer communications session, and priority information communicated in the page signal.

If the decision of sub-step 2014 is to establish a link with the base station which transmitted the page, then operation proceeds to sub-step 2016, where the first wireless terminal terminates the peer to peer communications session and in sub-step 2018 establishes a link with the base station. However, if the first wireless terminal decides in sub-step 2014 to continue with the ongoing peer to peer communication session, operation proceeds from sub-step 2014 to sub-step 2020 where the first wireless terminal continues with the peer to peer communications session. In some such embodiments, the first wireless terminal, when deciding to perform sub-step 2020, the first wireless terminal ignores the page, e.g., with no response back to the base station. In other embodiments, the first wireless terminal, when deciding to perform sub-step 2020, sends a page response signal to the base station indicating the first wireless terminal has received the page but has decided not to establish a link with the base station.

Returning to step 2024, in step 2024, a second wireless terminal, capable of supporting peer to peer node operations and cellular network operations, is operated. Step 2024 includes sub-steps 2026 and 2028. In sub-step 2026, the second wireless terminal monitors for paging signals from a base station during a third set of time intervals which are paging time intervals. In some such embodiments, the first and third paging time intervals overlap. In sub-step 2028, the second wireless terminal, during said second set of time intervals, which does not overlap with said first or third set of time intervals participates in a peer to peer communications session.

Returning to step 2030, in step 2030, a third wireless terminal is operated in a peer to peer communications session during which at least some first time periods occur, wherein the third wireless terminal does not perform paging operations between the start and end of its peer to peer communications session and remains silent during the first time intervals occurring between the start and end of its peer to peer communications session.

FIG. 29 is a drawing of an exemplary wireless terminal 3100, e.g., mobile node, in accordance with various embodiments. Exemplary wireless terminal 3100 monitors for, detects, and processes paging signals in a wireless communications system including dual mode capability including access node based cellular communications and peer to peer communications, and exemplary wireless terminal 3100 supports operation in both modes of operation.

Exemplary wireless terminal 3100 includes a receiver module 3102, a transmitter module 3104, a processor 3106, user I/O devices 3108, and memory 3110 coupled together via a bus 3112 over which the various elements may exchange data and information. User I/O devices 3108 include, e.g., keypad, keyboard, switches, mouse, microphone, speaker, display, etc. User I/O devices 3108 are used for operation including inputting user data, accessing output user data, and controlling at least some functions and operations of the wireless terminal, e.g., initiating a peer to peer communications session or initiating an access node based communications session.

Receiver module 3102, e.g., an OFDM receiver, coupled to receive antenna 3103 via which the wireless terminal receives signals from a base station including paging signals and signals in which the base station is functioning as a point of network attachment for wireless terminal 3100, e.g., downlink control signals ad downlink user data signals. Receiver module 3102 also receives signals from a peer node in a peer to peer communications session with wireless terminal 3100.

Transmitter module 3104, e.g., an OFDM transmitter, is coupled to transmit antenna 3105, via which the wireless terminal 3100 transmits signals. Transmitted signals include generated identification signals 3142, e.g., an OFDM user beacon signal including beacon signal burst, each beacon signal burst including at least one OFDM beacon symbol. Transmitted signals also include access node based session establishment signals, peer to peer session establishment signals, control and user data uplink signals directed to a base station serving as the wireless terminal's point of network attachment, signals directed to a peer node as part of a peer to peer communications session, and uplink page response signals directed to the base station which transmitted the page directed to wireless terminal 3100.

Memory 3110 includes routines 3114 and data/information 3116. The processor 3106, e.g., a CPU, executes the routines 3114 and uses the data/information 3116 in memory 3110 to control the operation of the wireless terminal and implement methods. Routines 3114 include a communications routine 3118 and wireless terminal control routines 3120. The communications routine 3118 implements the various communications protocols used by the wireless terminal 3100. The wireless terminal control routines 3120 include a time interval determination module 3122, a cellular network communications module 3124, a page signal monitoring module 3126, a peer to peer communications module 3128, a wireless terminal identification signal generation module 3130, a decision module 3132, and a peer to peer communications session termination module 3134. The peer to peer communications module 3128 includes a peer to peer communications control module 3129.

Data/information 3116 includes a determined first set of time intervals 3136, which are paging time intervals, a determined second set of time intervals 3138, a detected page signal 3140, a generated wireless terminal identification signal, e.g., a generated user beacon associated with wireless terminal 3100, paging band information 3144, peer to peer band information 3146 and receiver band setting information 3148.

Time interval determination module 3122 determines first and second sets of time intervals (3136, 3138), respectively), the first and second sets of time intervals being non-overlapping sets, the first set of time intervals being paging time intervals. Cellular network communications module 3124 supports cellular network communications operations, e.g., operations in which the wireless terminal uses the base station as a network attachment point to communicate with another wireless terminal via the cellular communications network. Page signal monitoring module 3126 monitors for paging signals from a base station during the first set of time intervals 3136. Information 3140 represents a detected page signal directed to wireless terminal 3100.

Peer to peer communications module 3128 supports peer to peer communications signaling operations during the second set of time intervals 3138 but not during the first set of time intervals 3136. Peer to peer transmission control module 3129 restrains the wireless terminal from transmitting peer to peer signals during the first time intervals. In some embodiments, the wireless terminal is also controlled to suspend detection operations of peer to peer signals during the first time intervals. In various embodiments, members of the first set of time intervals are interleaved with members of the second set of time intervals.

Wireless terminal identification signal generation module 3130 generates a wireless terminal identifier 3142 used for peer to peer communications e.g., an OFDM beacon signal burst or sequence of bursts, each beacon signal burst including at least one beacon symbol. Decision module 3132 decides between establishing a communication link with a base station in response to a page which was received or continuing with an on-going peer to peer communications session. Peer to peer communications session termination module 3134 terminates a peer to peer communications session in response to a received page directed to the wireless terminal 3100.

Paging band information 3144 includes information identifying the frequency band used for paging, while peer to peer band information 3146 identifies the frequency band used for peer to peer communications. In some embodiments the same frequency band is used for paging and peer to peer communications. In some embodiments, different frequency bands are used for paging and peer to peer communications. In some such embodiments, receiver module 3102 includes a tunable receiver responsive to a mode control signal for switching between the different frequency bands used for paging and peer to peer communications. Receiver band setting information 3148 includes information indicating the current setting of the receiver module 3102 and control signaling used to change the setting of the receiver module 3102.

FIG. 30 is a drawing of an exemplary communications system 2100 in accordance with various embodiments. Exemplary communications system 2100 includes a plurality of base stations (base station 1 2102, base stations 2 2104, base station 3 2106) and a plurality of non-access beacon signal transmitter nodes (non-access beacon signal transmitter node 1 2108, non-access beacon signal transmitter node 2 2112, non-access beacon signal transmitter node 3 2110). The base stations (2102, 2104, 2106) are coupled to network nodes (2114, 2118, 2118) via network links (2120, 2128, 2126), respectively. In addition, system 2100 includes network node 2116 which is coupled to (network node 2114, network node 2118, non-access beacon signal transmitter 2108, and other network nodes and/or the Internet) via network links (2122, 2124, 2130, 2131), respectively. Network links (2120, 2122, 2124, 2126, 2128, 2130, 2131), are, e.g., fiber optic links and/or wired links.

Some of the base stations (BS 1 2102, BS 2 2104) support both peer to peer communications in the base station region and also operate as access nodes. Base station 3 2106 functions as an access node and does not support peer to peer communications in its coverage region. Each base station (BS 1 102, BS 2 2104, BS 3 2106) has a corresponding region (2103, 2105, 2107) which represents a cellular coverage area when in the network access mode. Regions (2103, 2105) also represent base station beacon transmission regions when supporting peer to peer communications.

The base stations (2102, 2104, 2106) and the non-access beacon signal transmitter nodes (2108, 2110, 2112) transmit beacon signals including beacon signal bursts, e.g., OFDM beacon, signal bursts each beacon signal burst including at least one beacon symbol.

Exemplary system 2100 also includes a plurality of wireless terminals, e.g., mobile nodes, (MN 1 2150, MN 2 2152, MN 3 2154, MN 4 2156, MN 5 2158, MN 6 2160, MN 7 2162, MN 8 2164), which may move throughout the system. MN 1 2150 is using BS 1 2102 as an access node and is coupled to BS 1 2102 via link 2166. MN 2 2152 is using BS 1 2102 as an access node and is coupled to BS 1 2102 via link 2168. MN 1 2150 and MN 2 2152 are using access node beacon signals transmitted from BS 1 2102 for synchronization. MN 3 2154 is in a peer to peer communications session with MN4 2156 using peer to peer link 2170. MN 3 2154 and MN 4 2156 are using peer to peer beacon signals from BS 1 2102 for synchronization purposes.

MN 5 2158 is using BS 3 2106 as an access node and is coupled to BS 3 2106 via link 2172. MN 6 2160 is using BS 3 2106 as an access node and is coupled to BS 3 2106 via link 2174. MN 5 2158 and MN 6 2160 are using access node beacon signals transmitted from BS 3 2174 for synchronization.

MN 7 2162 is in a peer to peer communications session with MN 8 2164 using peer to peer link 2176. MN 7 2162 and MN 8 2164 are using peer to peer beacon signals from non-access beacon signal transmitter node 3 2110 for synchronization purposes.

Base station 1 2102 includes a peer to peer beacon signal generation module 2132, all access node beacon signal generation module 2134, a transmitter module 2136, a receiver module 2138 and a switching module 2140. Peer to peer beacon signal generation module 2132 generates beacon signals used to support peer to peer communications, while access node beacon signal generation module 2134 generates beacon signals used to support cellular network communications. Transmitter module 2136, e.g., an OFDM transmitter, transmits generated peer to peer beacon signals and generated access node beacon signals. Transmitter module 2136 also transmits control and user data signals to wireless terminals when functioning as an access node. Receiver module 2138, e.g., an OFDM receiver, receives signals such as access request signals, control signals and user data from wireless terminals, e.g., mobile nodes using the base station as a point of network attachment. Switching module 2140 supports switching between peer to peer and cellular modes of operation using the same frequency band for peer to peer and cellular nodes of operation at different times. Base station 1 2102 transmits different beacon signals during peer to peer and cellular modes of operation.

Non-access beacon signal transmitter node 2 2112 and non-access beacon signal transmitter node 3 2110 are stand alone devices. Non-access beacon signal transmitter node 2 2112 includes a transmitter 2142, a battery 2144 and a receiver 2146. Battery 2144 powers non-access beacon signal transmitter node 2 2112. Transmitter 2142 transmits beacon signals which are utilized by mobile nodes in its transmitter coverage region 2113 for synchronization purposes in supporting peer to peer communications sessions. The beacon signal transmitter 2142 does not relay any user data. Receiver 2146 receives a broadcast signal used for timing synchronization purposes. The receiver 2146 for receiving a broadcast signal used for timing synchronization purposes is one of a GSM receiver, a satellite receiver, and a cellular network receiver. Satellite receivers include, e.g., a GPS receiver, broadcast TV and/or radio signal satellite receiver, proprietary satellite receiver or government controlled satellite receiver. Cellular network receivers include, e.g., CDMA, OFDM, GSM, etc., receivers. In some embodiments, a non-access beacon signal transmitter node includes a plurality of different types of receivers for receiving different types of broadcast signals, e.g., with different signals being available in some areas but not in others.

In various embodiments, at least some of the base stations, which transmit beacon signals are not synchronized with respect to one another. In various embodiments, at least some of the non-access beacon signal transmitter nodes, which transmit beacon signals, are not synchronized with respect to one another. For example, non-access beacon signal transmitter node 3 2110, in some embodiments, does not include a receiver, and its transmitted beacon signals into its transmitter region 2111 are free running with respect to the other non-access beacon signal transmitters in system 2100 and the base stations in system 2100.

Non-access beacon signal transmitter module 3 2110 includes a solar cell 2148, and the solar cell 2148 is a solar power source conversion device for powering non-access beacon signal transmitter node 3 2110 during at least some of the time.

Non-beacon access beacon signal transmitter node 1 2108 is coupled to the network via link 2130 thus facilitating timing synchronization information to be communicated to the node 2108, allowing for its beacon signal transmission into its transmitter region 2109 to be synchronized with respect to an overall system timing reference. No user data is communicated over link 2130.

FIG. 31 is a drawing of an exemplary wireless communications system 2200 which supports both peer to peer communications and cellular communications in accordance with various embodiments. Exemplary communications system 2200 includes a plurality of wireless terminals, e.g., mobile nodes, and a plurality of base stations. At least some of the plurality of base stations are both network access node and peer to peer capable such as exemplary base station 2212. Exemplary communications system 2220 also includes some base stations which function as access nodes but do not support peer to peer communications such as exemplary base station 2280 and some non-access beacon signal transmitter nodes for supporting peer to peer communications such as exemplary non-access beacon signal transmitter node 2282.

System 2200 includes wireless terminal 1A 2202 and wireless terminal 1B 2204, which both support peer to peer and cellular communications; wireless terminal 2A 2206 and wireless terminal 2B 2210, which both support peer to peer communications but not cellular network communications; and wireless terminal 3 2208 which supports cellular network communications but not peer to peer communications.

Wireless terminal 1A 2202 includes a beacon signal processing module 2216, a peer to peer communications module 2218, a cellular network communications module 2230, a mode control module 2232, current mode information 2234 and subscriber plan identification information 2236. Beacon signal processing module 2216 processes beacon signals received from base stations and/or non-access beacon signal transmitter nodes. The beacon signals are uses for supporting cellular and peer to peer communications, e.g., providing synchronization, identification, mode and/or priority information. Peer to peer communications module 2218 performs operations supporting peer to peer communications. Cellular network communications module 2230 performs operations supporting cellular communications in which the wireless terminal 1A 2202 is communicating via a wireless communications link with a base station functioning as an access node and providing a point of network attachment. Mode control module 2232 switches between peer to peer and cellular modes of operation, as wireless terminal 1A 2202 supports at most one of peer to peer mode and cellular mode operation at a given time. Current mode information 2234 indicates which of the peer to peer mode and cellular mode wireless terminal 1A 2202 is currently operating in.

Wireless terminal 1B 2204 includes a beacon signal processing module 2238, a peer to peer communications module 2240, a cellular network communications module 2242, a communications control module 2244, and subscriber plan identification information 2246. Beacon signal processing module 2238 processes beacon signals received from base stations and/or non-access beacon signal transmitter nodes. Peer to peer communications module 2240 performs operations supporting peer to peer communications. Cellular network communications module 2242 performs operations supporting cellular communications in which the wireless terminal 1B 2204 is communicating via a wireless communications link with a base station functioning as an access node and providing a point of network attachment. Communications control module 2244 switches between peer to peer and cellular modes of operation, as wireless terminal 1A 2202 controls the wireless terminal to maintain peer to peer and cellular network communications sessions at the same time.

Wireless terminal 2A 2206 includes a beacon signal processing module 2248, a peer to peer communications module 2250, and subscriber plan identification information 2252. Beacon signals processing module 2248 processes beacon signals received from base stations and/or non-access beacon signal transmitter nodes. Peer to peer communications module 2250 performs operations supporting peer to peer communications. Wireless terminal 2B 2210 includes a beacon signal processing module 2260, a peer to peer communications module 2262, and subscriber plan identification information 2264. Beacon signal processing module 2260 processes beacon signals received from base stations and/or non-access beacon signal transmitter nodes. Peer to peer communications module 2262 performs operations supporting peer to peer communications.

Wireless terminal 3 2208 includes a beacon signal processing module 2254, a cellular network communications module 2256, and subscriber plan identification information 2258. Beacon signal processing module 2254 processes beacon signals received from base stations and/or non-access beacon signal transmitter nodes. Cellular network communications module 2256 performs operations supporting cellular network communications.

Base station 2212 includes a beacon transmission module 2213. Beacon signal transmission module 2213 transmits beacon signals used for communications synchronization, identification, mode, and/or priority information. In some embodiments, at least some of the beacon signals are OFDM beacon signals including beacons signal bursts, each beacon signal burst including at least one beacon symbol. Base station 2212 is coupled to other network nodes, e.g., other base station, routers, AAA nodes, home agent nodes, etc, and/or the Internet via link 2214. Base station 2280 is coupled to other network nodes and/or the Internet via network link 2281. Network links 2214, 2281 are, e.g., fiber optic links and/or wired links.

Dotted line 2268 between wireless terminal 1A 2202 and base station 2212 indicates that WT 1A 2202 can operate in a cellular communication mode and have a wireless communication link with a base station. Dotted line 2266 between wireless terminal 1A 2202 and WT 2A 2206 2212 indicates that WT 1A 2202 and WT 2A 2206 can operate in a peer to peer communications mode and have a wireless communication link with another wireless terminal. The lines 2266 and 2268 have been indicated as dotted lines to indicate that WT 1A 2202 switches between the two modes.

Solid the 2274 between wireless terminal 1B 2204 and base station 2212 indicates that WT 1B 2204 can operate in a cellular communication mode and have a wireless communication link with a base station. Solid line 2272 between wireless terminal 1B 2204 and WT 2B 2206 2210 indicates that WT 1B 2204 and WT 2B 2210 can operate in a peer to peer communications mode and have a wireless communication link with another wireless terminal. The lines 2272 and 2274 have been indicated as solid lines to indicate that WT 1B can maintain peer to peer and cellular network communications sessions at the same time.

Line 2270 between wireless terminal 3 2208 and base station 2212 indicates that WT 3 2208 can operate in a cellular communication mode and have a wireless communication link with a base station.

The various wireless terminals (2202, 2204, 2206, 2208, 2210) include subscriber plan identification information (2236, 2246, 2252, 2258, 2264), respectively. In some embodiments, a set of wireless terminals correspond to a communications service subscriber who subscribes to a family plan which supports multiple communications devices some of which have different capabilities. For example, in one embodiment, the set of wireless terminals corresponding to the communications service subscriber who subscribes to a family plan includes WT1A 2202, WT 1B 2204, WT 2A 2206, and WT 3 2208.

In some embodiments, the peer to peer communications modules (2218, 2240, 2250, 2262) are OFDM communications modules. In some embodiments the cellular network communications modules (2230, 2242, 2256) are OFDM communications modules. In some embodiments, the peer to peer communications modules (2218, 2240, 2250, 2262) are OFDM communications modules, and the cellular network communications modules (2230, 2242, 2256) are CDMA communications modules. In some embodiments, the peer to peer communications modules (2218, 2240, 2250, 2262) are OFDM communications modules, and the cellular network communications modules (2230, 2242, 2256) are GSM communications modules.

FIG. 32 is a drawing 3200 illustrating exemplary beacon burst time position hopping in accordance with various embodiments. Horizontal axis 3202 represents time while vertical axis 3204 represents frequency, e.g., OFDM tones in a frequency band, e.g., a non-infrastructure frequency band being used for peer to peer communications. A wireless terminal receives an external broadcast signal 3206 which the wireless terminal uses a timing reference signal and upon which it bases its timing structure. The external reference signal repeats as indicated by signal 3206. In some embodiments, the timing reference point is derived from information conveyed by the received broadcast signal. In this example, the peer to peer timing structure being used by the wireless terminal includes a sequence of slots used for beacon signaling, each time slot is associated with a beacon signaling resource (slot 1 beacon signaling resource 3208, slot 2 beacon signaling resource 3210, slot 3 beacon signaling resource 3212. The slots repeat as indicated by slot 1 beacon signaling resource 3208. Each slot beacon signaling resource represents a block of air link resources, e.g., OFDM tone-symbols.

The start of each beacon signaling resources slot (3208, 3210, 3212) is referenced with respect a predetermined timing offset (T1 3214, T2 3216, T3 3218). In some embodiments, the time duration of each beacon signaling slot is the same. In some embodiments T2 −T1 =T 3 −T2.

Within each beacon signaling slot resource (3208, 3210, 3212), the wireless terminal transmits a beacon signal burst (3220, 3222, 3224) including at least one beacon symbol (3226, 3228, 3230), the beacon symbol being a relatively high power symbol with respect to data symbols transmitted by the wireless terminal. In this example, the time position of the beacon signal burst with the beacon resource slot is hopped from one slot to the next in accordance with a hopping function used by the wireless terminal. The hopping function varies the time of the beacon signal burst from the start of the slot as indicated by different time offset values (T4 3234, T5 3236, T6 3238) corresponding to (slot 1, slot 2, slot 3), respectively. The hopping function determines the time offset as a function of a wireless terminal identifier, a user identifier, and/or a priority level value. In some embodiments, other inputs can be used by the hopping function, e.g., a received broadcast value associated with the spectrum, a received key, a value associated with a designated area, a value associated with a sector etc.

In this example, the same tone is used by the wireless terminal for the beacon symbol (3226, 3228, 3230, 3226′) of the beacon signal bursts (3220, 3220, 3224, 3220′) respectively, in slots resources (3208, 3210, 3212, 3208′), respectively. Different wireless may, and sometimes do use a different tone for the beacon symbol.

FIG. 33 is a drawing 3300 illustrating exemplary beacon burst time position hopping and beacon symbol tone hopping in accordance with various embodiments. Horizontal axis 3302 represents time while vertical axing 3304 represents frequency, e.g., OFDM tones in a frequency band, e.g., a non-infrastructure frequency band being used for peer to peer communications. A wireless terminal receives an external broadcast signal 3306 which the wireless terminal uses a timing reference signal and upon which it bases its timing structure. The external reference signal repeats as indicated by signal 3306′. In some embodiments, the timing reference point is derived from information conveyed by the received broadcast signal. In this example, the peer to peer timing structure being used by the wireless terminal includes a sequence of slots used for beacon signaling, each time slot is associated with a beacon signaling resource (slot 1 beacon signaling resource 3308, slot 2 beacon signaling resource 3310, slot 3 beacon signaling resource 3312). The slots repeat as indicated by slot 1 beacon signaling resource 3308′. Each slot beacon signaling resource represents a block of air link resources, e.g., OFDM tone-symbols.

The start of each beacon signaling resources slot (3308, 3310, 3312) is referenced with respect a predetermined timing offset (T1 3314, T2 3316, T3 3318) from the external timing reference signal 3306. In some embodiments, the time duration of each beacon signaling slot is the same. In some embodiments T2 −T1 =T3 −T2.

Within each beacon signaling slot resource (3308, 3310, 3312), the wireless terminal transmits a beacon signal burst (3320, 3322, 3324) including at least one beacon symbol (3326, 3328, 3330), the beacon symbol being a relatively high power symbol with respect to data symbols transmitted by the wireless terminal. In this example, the time position of the beacon signal burst with the beacon resource slot is hopped from one slot to the next in accordance with a time hopping function used by the wireless terminal. The hopping function varies the time of the beacon signal burst from the start of the slot as indicated by different time offset values (T4 3334, T5 3336, T6 3338) corresponding to (slot 1, slot 2, slot 3), respectively. The hopping function determines the time offset as a function of a wireless terminal identifier, a user identifier, and/or a priority level value. In some embodiments, other inputs can be used by the hopping function, e.g., a received broadcast value associated with the spectrum, a received key, a value associated with a designated area, a value associated with a sector, etc.

In this example, the tone of the beacon signal used by the wireless terminal for the beacon symbol (3326, 3328, 3330) of the beacon signal bursts (3320, 3322, 3324), respectively, in slots resources (3308, 3310, 3312), respectively, is also hopped from one slot to another in accordance with a tone hopping function. Inputs to the tone hopping function include one or more of a wireless terminal identifier, a user identifier, a priority level value, a received broadcast value associated with the spectrum, a received key, a value associated with a designated area, and a value associated with a sector.

In this example, the next iteration of beacon signaling resource slot 1 3308′ has the beacon symbol 3326′ of beacon burst 3320′ placed in the same OFDM tone-symbol position of the resource 3308′ as the beacon symbol 3326 of beacon burst 3320 in resource 3308. In some embodiments, two separate hopping functions are used, one for beacon burst time hopping and the other for tone hopping. In some embodiments, the beacon burst time position hopping function and the tone hopping function have the same sequence length. In some embodiments, the beacon burst time position hopping function and the tone hopping function have different sequence lengths. For example, the two sequence lengths may be co-prime with each other. Alternatively, the ratio of one sequence length to the other sequence length may be an integer. In other embodiments, one hopping function is used for both beacon burst time hopping and tone hopping. Specifically, suppose that each beacon signaling resource slot 3308, 3310, 3312 includes M symbol times and every symbol time includes N tones. Then, in each slot, the hopping function outputs a number, which uniquely identities one specific tone at one specific symbol time. For example, the number can be 0, 1, . . ., M*N−1, where M and N are positive integers. In some embodiments, N is at least 100 and M is at least 20, although in other embodiments, the values may be smaller.

FIG. 34 is a drawing 3400 illustrating exemplary coordinated timing in a peer to peers communications band in accordance with various embodiments. Drawing 3400 includes exemplary 1^(st) and 2^(nd) wireless terminal (3402, 3404), e.g., peer mobile nodes. Upper drawing portion 3401 is used to illustrate operations of wireless terminal 1 3402, while lower drawing portion 3403 is used to illustrate operations of wireless terminal 2 3404. Horizontal axes 3406 represents time, while vertical axes 3408 represents frequency, e.g., OFDM tones in the peer to peer frequency band.

Both wireless terminals (3402, 3404) receive and use external broadcast signal 3410 to obtain timing reference. Based on the timing reference signal 3410, both wireless terminals (3402, 3404) recognize beacon signaling resource slots 3412 and 3414. Wireless terminal 1 3402 transmits a beacon signal burst 3416 including beacon symbol 3418 during time interval 3440, and beacon signal burst 3420 including beacon symbol 3422 during time interval 3442. Wireless terminal 2 3404 is monitoring for beacon symbols from other wireless terminals during time intervals 3444, 3446, 3448, and 3450. Since time interval 3440 is with time interval 3446 wireless terminal 2 is able to detect the beacon symbol 3418 from wireless terminal 1 3402. Since time interval 3442 is within time interval 3450 wireless terminal 2 is able to detect the beacon symbol 3422 from wireless terminal 1 3402.

Wireless terminal 2 3404 transmits a beacon signal burst 3424 including beacon symbol 3426 during time interval 3452, and beacon signal burst 3428 including beacon symbol 3430 during time interval 3454. Wireless terminal 1 3402 is monitoring for beacon symbols from other wireless terminals during time intervals 3432, 3434, 3436, and 3438. Since time interval 3452 is within time interval 3432 wireless terminal 1 is able to detect the beacon symbol 3426 from wireless terminal 2 3404. Since time interval 3454 is within time interval 3436 wireless terminal 1 is able to detect the beacon symbol 3430 from wireless terminal 2 3404.

In this example, both wireless terminals are able to detect beacon signals from each other. The coordinated timing structure based on a reference allows efficient operation and reduced power consumption, since modules within a wireless terminal can be powered down when transmission and/or monitoring is not required, e.g., during silence modes of operation.

Time hopping of the beacon burst, e.g., as a function of a wireless terminal identifier, facilitates resolution of a problem where both wireless terminal 1 and wireless terminal 2 should happen to transmit a beacon signal burst during one beacon signaling resource slot. In some embodiments, the beacon burst time hopping is structured so that at least some beacon signal bursts transmitted by two peer wireless terminals will be non-overlapping. In some embodiments, a wireless terminal, occasionally refrains from transmitting its beacon burst during a beacon signaling resource and monitors for the full duration of the beacon signaling resource.

Additional embodiments, features and variations will now be discussed.

An infrastructure network usually includes a base station, which provides service to terminals in a given geographical area. In an exemplary embodiment, a base station of an infrastructure network uses a first (infrastructure) spectrum band to provide service in a geographical area. Meanwhile, a second (non-infrastructure) spectrum band, which is different from the infrastructure spectrum band, is also available for the terminals in the area, e.g., to be used for an ad hoc network.

In accordance with various embodiments, in order to facilitate the timing and/or frequency synchronization in the ad hoc network using the non-infrastructure spectrum band, the infrastructure base station transmits a beacon signal.

In an exemplary embodiment, the base station transmits the beacon signal in the infrastructure spectrum band. The desired common timing and/or frequency reference to be used in the non-infrastructure spectrum band can be determined from the beacon signal. In addition, the base station may, and sometimes does, send system information about the frequency location of the non-infrastructure spectrum band and the type of service provided in the non-infrastructure spectrum band, e.g., TDD (time division duplex) or ad hoc networking. The system information is sent using the beacon signal and/or other broadcast control signals.

A wireless terminal first tunes to the infrastructure spectrum band to detect the beacon signal and derives the timing and/or frequency reference to be used in the non-infrastructure spectrum band. The wireless terminal further receives the system information from the beacon and/or other broadcast control signals, and determines the frequency location of the non-infrastructure spectrum band, e.g., carrier frequency. The wireless terminal tunes to the non-infrastructure spectrum band and uses the acquired timing and/or frequency synchronization to start a communication link in the non-infrastructure spectrum band.

In another embodiment, the base station transmits the beacon signal in the non-infrastructure spectrum band, so that if the wireless terminal directly tunes to the non-infrastructure spectrum band, the wireless terminal can derive the desired common timing and/or frequency reference from the beacon signal. In that embodiment, the base station may, and sometimes does, additionally transmit beacon and/or other broadcast control signals in the infrastructure spectrum band as well as send system information about the frequency location of the non-infrastructure spectrum band and the type of service provided in the non-infrastructure spectrum band.

In yet another embodiment, in which the infrastructure spectrum band may not exist, a special transmitter is set in a geographic area to transmit a system beacon signal in each of the non-infrastructure spectrum bands that are available for use in the vicinity of the geographical area in which the special transmitter sits. In one embodiment, at a given time, the special transmitter transmits at most one beacon signal burst in a spectrum band. The special transmitter hops across each of the available spectrum bands and transmits the beacon signal burst successively from one spectrum band to another. A wireless terminal is to scan a candidate spectrum band to see whether a system beacon signal can be detected in the candidate spectrum band. If a system beacon signal is detected, then the candidate spectrum band is available for use. Otherwise, the wireless terminal, in some embodiments, is not allowed to use the candidate spectrum band, in which case the wireless terminal may have to scan another candidate spectrum band to find an available spectrum band to use.

After the wireless terminal obtains the timing and/or frequency reference from the beacon signal, the wireless terminal then tunes to the non-infrastructure spectrum band. The wireless terminal, in some embodiments, starts to transmit its own user beacon signal in the non-infrastructure spectrum band. Similar to the beacon signal sent by the infrastructure base station, the user beacon signal also includes a sequence of beacon signal bursts in a spectrum band. However, the user beacon signal, in some embodiments, is different from the beacon signal sent by the infrastructure base station in at least one of the following ways: the periodicity of the beacon signal bursts, the tone used in a beacon signal burst, and the hopping pattern of the tones used in successive beacon signal bursts. The wireless terminal may, and sometimes does, further listen to the non-infrastructure spectrum band to detect the presence of a user beacon signal sent by another wireless terminal. In some embodiments, the wireless terminal determines transmission and/or detection of user beacon signals as a function of the timing and/or frequency reference from the beacon signal sent by the infrastructure base station. When wireless terminals derive their timing and/or frequency reference from the same source, e.g., the same infrastructure base station beacon signal, it is easy for them to detect each other's presence and to establish communication links.

In accordance with a feature of some exemplary embodiments, while a wireless terminal is in a peer-to-peer communication session in the non-infrastructure spectrum band, the wireless terminal may, and sometimes does, periodically suspend the session for a short time period and tune to the infrastructure spectrum band, e.g., to check whether there is a page for the terminal. The time periods in which the wireless terminal checks pages are, in some embodiments, pre-determined, so that both the wireless terminal and the base station can be synchronized on when a page should be delivered. In some embodiments, a set of wireless terminals in the peer-to-peer communication sessions have a common time period in which each of those wireless terminals suspend the sessions in the non-infrastructure spectrum band and check pages in the infrastructure spectrum band. Advantageously, this synchronization helps reduce the wastage of session time in the peer-to-peer sessions.

In accordance with various embodiments, the infrastructure base station also provides service in the non-infrastructure spectrum band, e.g., to provide peer-to-peer communication service and/or to provide TDD service. The base station in some embodiments transmits the beacon signal in such a way that after the wireless terminal receives the beacon signal the wireless terminal can predict the signal quality of a data session if the wireless terminal is to establish a communication link with the base station. In one embodiment, the transmission power of the beacon signal is the same for each of such base stations. In another embodiment, the data session, e.g., at a given coding and modulation rate, is sent at a transmission power, which is a function of the transmission power of the beacon signal. For example, the per minimum transmission unit transmission power of the data session is a fixed dB amount, e.g., 10 dBs or 16 dBs, below the transmission newer of the beacon symbols of the beacon signal.

While described primarily in the context of an OFDM system, the methods and apparatus of various embodiments are applicable to a wide range of communications systems including many non-OFDM, and/or many non-cellular systems.

In various embodiments nodes described herein are implemented using one or more modules to perform the steps corresponding to one or more methods, for example, generating a beacon signal, transmitting a beacon signal, receiving beacon signals, monitoring for beacon signals, recovering information from received beacon signals, determining a timing adjustment, implementing a timing adjustment, changing a mode of operation, initiating a communication session, etc. In some embodiments various features are implemented using modules. Such modules may be implemented using software, hardware or a combination of software and hardware. Many of the above described methods or method steps can be implemented using machine executable instructions, such as software, included in a machine readable medium such as a memory device, e.g., RAM, floppy disk, etc. to control a machine, e.g., general purpose computer with or without additional hardware, to implement all or portions of the above described methods, e.g., in one or more nodes. Accordingly, among other things, various embodiments are directed to a machine-readable medium including machine executable instructions for causing a machine, e.g., processor and associated hardware, to perform one or more of the steps of the above-described method(s).

Numerous additional variations on the methods and apparatus described above will be apparent to those skilled in the art in view of the above descriptions. Such variations are to be considered within scope. The methods and apparatus of various embodiments may be, and in various embodiments are, used with CDMA, orthogonal frequency division multiplexing (OFDM), and/or various other types of communications techniques which may be used to provide wireless communications links between access nodes and mobile nodes. In some embodiments the access nodes are implemented as base stations which establish communications links with mobile nodes using OFDM and/or CDMA. In various embodiments the mobile nodes are implemented as notebook computers, personal data assistants (PDAs), or other portable devices including receiver/transmitter circuits and logic and/or routines, for implementing the methods of various embodiments. 

What is claimed is:
 1. A method of operating a wireless device, the method comprising: monitoring for broadcast signals from a base station; determining from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum from one of: i) infrastructure use and ii) peer to peer use during which said spectrum is used for peer to peer communications to the other one of: i) infrastructure use and ii) peer to peer use; determining from said received beacon signal whether spectrum is allocated for infrastructure use or peer to peer use; and in response to detecting a reallocation of frequency spectrum from a peer to peer use to an infrastructure use, reducing a transmission power.
 2. The method of claim 1, further comprising: in response to detecting a reallocation of frequency spectrum from an infrastructure use to peer to peer use, ceasing to maintain a link established with said base station.
 3. The method of claim 1, further comprising: continuing, at a reduced transmission power level, a peer to peer communications session that was ongoing at the time transmission power was reduced in response to detecting reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 4. The method of claim 1, wherein determining from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum includes determining if there has been a change in information communicated by said received beacon signal relative to information communicated in a previously received beacon signal.
 5. The method of claim 2, wherein information communicated by said beacon signal indicates a peer to peer mode of frequency spectrum use.
 6. The method of claim 5, further comprising: switching from a cellular mode of operation to a peer to peer mode of operation in response to detecting a predetermined change in at least one of said broadcast signals.
 7. The method of claim 2, further comprising: ceasing communication with said base station in the frequency spectrum previously used by said communications link in response to detecting a predetermined change in the at least one of said broadcast signals.
 8. The method of claim 2, further comprising: continuing to monitor for signals from said base station after ceasing to maintain said link; and re-establishing a link with said base station in response to detecting a broadcast signal indicating a reallocation of said spectrum to infrastructure use.
 9. The method of claim 8, further comprising: maintaining device transmission silence between the time the device ceases to maintain said link and a link is re-established.
 10. The method of claim 9, wherein said wireless device remains in a coverage area corresponding to said base station between the time the link is ceased to be maintained and a link is re-established.
 11. The method of claim 8, further comprising: establishing a peer to peer communications session with another wireless terminal during at least a portion of the time between which said link is ceased to be maintained and a link is re-established.
 12. A wireless communications device, comprising: a link establishment module for establishing a communications link with a base station; a broadcast signal monitoring module for monitoring to detect broadcast signals from said base station while maintaining said communications link; a determination module configured to: determine from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum from one of: i) infrastructure use and ii) peer to peer use during which said spectrum is used for peer to peer communications to the other one of: i) infrastructure use and ii) peer to peer use and determine from said received beacon signal whether spectrum is allocated for infrastructure use or peer to peer use; and a mode control module for controlling the wireless communications device to operate in a peer to peer mode of operation when it is determined that spectrum is to be used for peer to peer mode communication and for controlling the wireless communications device to operate in a cellular mode of operation when it is determined that spectrum is to be used for cellular mode communication, said mode control module reducing a transmission power when said received beacon signal indicates a reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 13. The wireless communications device of claim 12, wherein said mode control module drops an established link with said base station when said received beacon signal indicates a reallocation of frequency spectrum from an infrastructure to a peer to peer use; and wherein said mode control module controls a control signaling module for generating control signals used to maintain said established link with said base station to stop generating control signals used to maintain said link when said control module drops said established link.
 14. The wireless communications device of claim 11, wherein said mode control module is configured to control the wireless communications device to continue, at a reduced transmission power level, a peer to peer communications session that was ongoing at the time transmission power was reduced in response to detecting reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 15. The wireless communications device of claim 11, wherein said determination module determines from said received beacon signal if said base station has reallocated frequency spectrum by determining if there has been a change in information communicated by said received beacon signal relative to information communicated in a previously received beacon signal.
 16. The wireless communications device of claim 13, wherein information communicated by said beacon signal indicates a peer to peer mode of frequency spectrum use.
 17. The wireless communications device of claim 16, wherein said mode control module includes: a switching module for switching from a cellular mode of operation to a peer to peer mode of operation in response to detecting a predetermined change in at least one of said broadcast signals.
 18. The wireless communications device of claim 13, further comprising: a link re-establishment module for re-establishing a link with said base station in response to detecting a broadcast signal indicating a reallocation of said spectrum to infrastructure use.
 19. The wireless communications device of claim 18, further comprising: a peer to peer communications establishment module for establishing a peer to peer communications session with another wireless terminal during at least a portion of the time between which said link is ceased to be maintained and a link is re-established.
 20. A wireless communications device, comprising: link establishment means for establishing a communications link with a base station; broadcast signal monitoring means for monitoring to detect broadcast signals from said base station while maintaining said communications link; means for determining from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum from one of: i) infrastructure use and ii) peer to peer use during which said spectrum is used for peer to peer communications to the other one of: i) infrastructure use and ii) peer to peer use means for determining from said received beacon signal whether spectrum is allocated for infrastructure use or peer to peer use; and mode control means for controlling the wireless communications device to operate in a peer to peer mode of operation when it is determined that spectrum is to be used for peer to peer mode communication and for controlling the wireless communications device to operate in a cellular mode of operation when it is determined that spectrum is to be used for cellular mode communication, said mode control means reducing a transmission power when said received beacon signal indicates a reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 21. The wireless communications device of claim 20, wherein said mode control means control the wireless communications device to drop an established link with said base station when said received beacon signal indicates a reallocation of frequency spectrum from an infrastructure to a peer to peer use.
 22. The wireless communications device of claim 20, wherein said mode control means control the wireless communications device to continue, at a reduced transmission power level, a peer to peer communications session that was ongoing at the time transmission power was reduced in response to detecting reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 23. The wireless communications device of claim 20, wherein said means for determining from said received beacon signal if said base station has reallocated frequency spectrum include means for determining if there has been a change in information communicated by said received beacon signal relative to information communicated in a previously received beacon signal.
 24. The wireless communications device of claim 21, wherein information communicated by said beacon signal indicates a peer to peer mode of frequency spectrum use.
 25. The wireless communications device of claim 21, further comprising: link re-establishment means for re-establishing a link with said base station in response to detecting a broadcast signal indicating a reallocation of said spectrum to infrastructure use.
 26. A non-transitory computer readable medium embodying machine executable instructions for controlling a wireless device, the non-transitory computer readable medium comprising: instructions for causing the wireless device to monitor for broadcast signals from a base station; instructions for causing the wireless device to determine from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum from one of: i) infrastructure use and ii) peer to peer use during which said spectrum is used for peer to peer communications to the other one of: i) infrastructure use and ii) peer to peer use; instructions for causing the wireless device to determine from said received beacon signal whether spectrum is allocated for infrastructure use or peer to peer use and instructions for causing the wireless device to reduce a transmission power when said received beacon signal indicates a reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 27. The non-transitory computer readable medium of claim 26, further comprising: instructions for causing the wireless device to drop an established link with said base station when said received beacon signal indicates a reallocation of frequency spectrum from an infrastructure to a peer to peer use.
 28. The non-transitory computer readable medium of claim 26, further comprising: instructions for causing the wireless communications device to continue, at a reduced transmission power level, a peer to peer communications session that was ongoing at the time transmission power was reduced in response to detecting reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 29. The non-transitory computer readable medium of claim 26, wherein said instructions for determining from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum includes instructions for determining if there has been a change in information communicated by said received beacon signal relative to information communicated in a previously received beacon signal.
 30. The non-transitory computer readable medium of claim 27, further comprising: instructions for causing the wireless device to cease communication with said base station in the frequency spectrum previously used by said communications link in response to detecting a predetermined change in at least one of said broadcast signals.
 31. The non-transitory computer readable medium of claim 27, further comprising: instructions for causing the wireless device to continue to monitor for signals from said base station after ceasing to maintain said link; and instructions for causing the wireless device to re-establish a link with said base station in response to detecting a broadcast signal indicating a reallocation of said spectrum to infrastructure use.
 32. An apparatus comprising: a wireless communications device processor configured to: monitor to detect broadcast signals from a base station; determine from a received beacon signal transmitted from said base station if said base station has reallocated frequency spectrum from one of: i) infrastructure use and ii) peer to peer use during which said spectrum is used for peer to peer communications to the other one of: i) infrastructure use and ii) peer to peer use; determine from said received beacon signal whether spectrum is allocated for infrastructure use or peer to peer use and control the apparatus to operate in a peer to peer mode of operation when it is determined that spectrum is to be used for peer to peer mode communication and for controlling the apparatus to operate in a cellular mode of operation when it is determined that spectrum is to be used for cellular mode communication, said apparatus reducing a transmission power when said received beacon signal indicates a reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 33. The apparatus of claim 32, wherein said wireless communications device processor is further configured to: drop an established link with said base station when said received beacon signal indicates a reallocation of frequency spectrum from an infrastructure to a peer to peer use.
 34. The apparatus of claim 32, wherein said communications device processor is further configured to control the apparatus to continue, at a reduced transmission power level, a peer to peer communications session that was ongoing at a time transmission power was reduced in response to detecting reallocation of frequency spectrum from a peer to peer use to an infrastructure use.
 35. The apparatus of claim 32, wherein said communications device processor is further configured to determine, as part of determining from a received beacon signal if said base station has reallocated frequency spectrum, if there has been a change in information communicated by said received beacon signal relative to information communicated in a previously received beacon signal.
 36. The apparatus of claim 33, wherein information communicated by said beacon signal indicates a peer to peer mode of frequency spectrum use.
 37. The apparatus of claim 33, wherein said wireless communications device processor is further configured to: re-establish a link with said apparatus in response to detecting a broadcast signal indicating a reallocation of said spectrum to infrastructure use.
 38. The method of claim 1, wherein said spectrum is used for both downlink and uplink signals when said spectrum is allocated for infrastructure use.
 39. The method of claim 1, wherein said received beacon signal has an average transmission power at least 10dB greater than the average transmission power of data signals transmitted from said base station. 